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3D (left and center) and 2D (right) representations of the terpenoid molecule atisane.
.A molecule is defined as an electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds.^ In most covalent compounds, molecules consist of groups of atoms held together by covalent or coordinate bonds.

^ Followings are some basic concepts of inorganic chemistry: Periodic Table - A molecule is a compound composed of a group of two or more atoms held together by chemical bonds.
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^ Write the formula of the neutral molecule;   the subscripts show the number of atoms needed to make the molecule neutral.

[1][2] Molecules are distinguished from polyatomic ions in this strict sense. .In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.^ In chemistry, a term often used to describe the dissolution of a gas into a liquid or solid.

.In the kinetic theory of gases, the term molecule is often used for any gaseous particle regardless of its composition.^ Often, the term is used for a reversible aggregation of particles in which the forces holding the particles together are weak and the colloid can be redispersed by agitation.

^ In chemistry, a term often used to describe the dissolution of a gas into a liquid or solid.

.According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.^ Consisting of molecules that have only single bonds (i.e.

^ Followings are some basic concepts of inorganic chemistry: Periodic Table - A molecule is a compound composed of a group of two or more atoms held together by chemical bonds.
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^ EXPLANATION :   Just as your demeanor and appearance change in different situations - in church, in   school, with friends, on a date, or on the playground - so do atoms change when they   react and bond with other atoms to form a molecule.

[3]
.A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O).^ Atom with aSymbol chemical symbol to the molecule.

^ Consisting of molecules that have only single bonds (i.e.

^ Pure water is a compound containing the chemical elements hydrogen      and oxygen.

.Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.^ Hydrogen with one valence electron forms a single covalent bond.
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^ Elements joined by ionic or covalent bonds .
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^ Consisting of molecules that have only single bonds (i.e.

.No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride).^ Ferrous chloride Ferrous chloride is a pale greenish salt-like crystal or powder, which is soluble in water.

^ Argyria is known to be caused by ingesting; 1) silver salts (compounds) such as silver nitrate, 2) high concentrations of ionic silver, 3) protein based silver products aka "silver protein" or "mild silver protein" .

^ The most familiar salt is sodium chloride , the principal component of common table salt.

The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. .In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals.^ Silver ions exist as individual entities in solution and do not cluster together to form particles like atoms.

^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ Atoms are called monovalent, divalent, trivalent, or tetravalent, according to whether they form one, two, three, or four bonds (see chemical bond ).

Contents

Molecular science

.The science of molecules is called molecular chemistry or molecular physics, depending on the focus.^ The strongly synthetic character of chemistry sets it apart from the "discovery" sciences such as physics, biology, astronomy and the Earth sciences.
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^ It is the study of the phenomena in these two categories, which constitute the sciences of chemistry and physics, respectively.
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.Molecular chemistry deals with the laws governing the interaction between molecules that results in the formation and breakage of chemical bonds, while molecular physics deals with the laws governing their structure and properties.^ Many of the chemical and physical properties of the transition elements are due to their unfilled d orbitals.

^ There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an independent species.

^ This is because water molecules help form hydrogen bonds between DNA's phosphate groups.
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In practice, however, this distinction is vague. .In molecular sciences, a molecule consists of a stable system (bound state) comprising two or more atoms.^ Followings are some basic concepts of inorganic chemistry: Periodic Table - A molecule is a compound composed of a group of two or more atoms held together by chemical bonds.
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^ Molecules are made up of one or more atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ For example, the molecular mass of water, which has two atoms of hydrogen and one atom of oxygen, is 18 (i.e., 2 + 16).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.Polyatomic ions may sometimes be usefully thought of as electrically charged molecules.^ A positive or negative electric charge possessed by an ion as a result of the gain or loss of one or more orbital electrons .

^ Ionic compounds do not have single molecules, being collections of oppositely charged ions.

^ A material that conducts electricity with ions as charge carriers.

The term unstable molecule is used for very reactive species, i.e., short-lived assemblies (resonances) of electrons and nuclei, such as radicals, molecular ions, Rydberg molecules, transition states, van der Waals complexes, or systems of colliding atoms as in Bose-Einstein condensate

History and etymology

.According to Merriam-Webster and the Online Etymology Dictionary, the word "molecule" derives from the Latin "moles" or small unit of mass.^ These chains are made up of small repeating units of molecules called monomers.
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^ Molecule is   the Latin word for "little mass."

  • Molecule (1794) - "extremely minute particle," from Fr. molécule (1678), from Mod.L. molecula, dim. of L. moles "mass, barrier". A vague meaning at first; the vogue for the word (used until late 18th century only in Latin form) can be traced to the philosophy of Descartes.
.Although the existence of molecules has been accepted by many chemists since the early 19th century as a result of Dalton's laws of Definite and Multiple Proportions (1803-1808) and Avogadro's law (1811), there was some resistance among positivists and physicists such as Mach, Boltzmann, Maxwell, and Gibbs, who saw molecules merely as convenient mathematical constructs.^ Such situation does not bother practical physicists, who just carry out routine calculations or experiments, as long as the rules of quantum theory yield consistent results, and it is kept in mind that mathematical models do not always make sense to our everyday experience.
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^ Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ How many total atoms are there in the neutral molecule?

The work of Perrin on Brownian motion (1911) is considered to be the final proof of the existence of molecules.
The definition of the molecule has evolved as knowledge of the structure of molecules has increased. .Earlier definitions were less precise, defining molecules as the smallest particles of pure chemical substances that still retain their composition and chemical properties.^ The smallest particle of a substance that has all of the physical and chemical properties of that substance.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ An atom is the smallest particle of an      element with the properties of that element.

^ A chemical substance added to a dispersion capable of maintaining the dispersed particles in suspension .

[4] .This definition often breaks down since many substances in ordinary experience, such as rocks, salts, and metals, are composed of large networks of chemically bonded atoms or ions, but are not made of discrete molecules.^ Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Molecules are made up of atoms that are bonded to one-another.

^ When an atom or molecule combines with oxygen, it tends to give up electrons to the oxygen in forming a chemical bond .

Molecular size

.Most molecules are far too small to be seen with the naked eye, but there are exceptions.^ An instrument that is used to look at cells and other small objects that cannot be seen with the eye alone.
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^ Molecules are small objects not susceptible of direct observation even under the most powerful microscope.
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.DNA, a macromolecule, can reach macroscopic sizes, as can molecules of many polymers.^ Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

The smallest molecule is the diatomic hydrogen (H2), with an overall length of roughly twice the 74 picometres (0.74 Å) bond length. .Molecules commonly used as building blocks for organic synthesis have a dimension of a few Å to several dozen Å.^ Cyclopropane carboxylic acid Cyclopropanecarboxylic acid is a clear liquid used in organic synthesis.

^ Isoprene ( H , C , V , JM ) The building block for terpenes and rubber, and the molecule that makes the Blue Ridge Mountains of Virginia, blue.
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^ In practice, there are a few commonly-used (and usually commercially available) electrode assemblies that have an electrode potential independent of the electrolyte used in the cell.

.Single molecules cannot usually be observed by light (as noted above), but small molecules and even the outlines of individual atoms may be traced in some circumstances by use of an atomic force microscope.^ When the distance separating individual atoms is only a few atomic diameters, the force of attraction can exceed 100,000 G-forces.

^ (Note: mono- is not affixed to first element of compound if there is only one atom per molecule, e.g., CO 2 is carbon dioxide, not monocarbon dioxide).
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^ Think of an      element as something that we can see and touch whereas a single atom is invisible even      in a microscope.

Some of the largest molecules are macromolecules or supermolecules.

Radius

.Effective molecular radius is the size a molecule displays in solution.^ Therefore, the effectiveness of colloidal solutions increases with decreasing particle size.

[5][6] The table of permselectivity for different substances contains examples.

Molecular formula

.A compound's empirical formula is the simplest integer ratio of the chemical elements that constitute it.^ Elements in a group have similar chemical properties and formulas.

^ Note: Isomers are chemical compounds with identical chemical formula but different arrangements of elements.
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^ The chemical formula for an ionic salt is an empirical formula; it does not represent a molecule but shows the proportion of atoms of the elements that make up the salt.

.For example, water is always composed of a 2:1 ratio of hydrogen to oxygen atoms, and ethyl alcohol or ethanol is always composed of carbon, hydrogen, and oxygen in a 2:6:1 ratio.^ Protein - Proteins are composed of carbon, hydrogen, oxygen, and nitrogen.
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^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
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^ Similarly, reduction referred to a decrease in the amount of oxygen in a substance or its complete removal, e.g., the reaction of cupric oxide and hydrogen to form copper and water.

.However, this does not determine the kind of molecule uniquely - dimethyl ether has the same ratios as ethanol, for instance.^ However, when molecules consist of several polar bonds, the arrangement of the bonds determines whether it is a polar or nonpolar molecule.
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.Molecules with the same atoms in different arrangements are called isomers.^ It has the same chemical formula as glucose (the chief source of energy for living organisms) but has a different arrangement of atoms.
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^ Note: Isomers are chemical compounds with identical chemical formula but different arrangements of elements.
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^ If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom).
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.Also carbohydrates, for example, have the same ratio (carbon:hydrogen:oxygen= 1:2:1) (and thus the same empirical formula) but different total numbers of atoms in the molecule.^ A small molecule made of one carbon and three hydrogen atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Protein - Proteins are composed of carbon, hydrogen, oxygen, and nitrogen.
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.The molecular formula reflects the exact number of atoms that compose the molecule and so characterizes different isomers.^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ Note: Isomers are chemical compounds with identical chemical formula but different arrangements of elements.
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^ The chemical formula for an ionic salt is an empirical formula; it does not represent a molecule but shows the proportion of atoms of the elements that make up the salt.

The empirical formula is often the same as the molecular formula but not always. For example the molecule acetylene has molecular formula C2H2, but the simplest integer ratio of elements is CH.
.The molecular mass can be calculated from the chemical formula and is expressed in conventional atomic mass units equal to 1/12th of the mass of a neutral carbon-12 (12C isotope) atom.^ The atoms in a molecule are shown by their atomic   symbols and the combination is the molecular formula .

^ The average atomic mass of an element compared to 1/12 the mass of carbon 12.

^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.For network solids, the term formula unit is used in stoichiometric calculations.^ In chemistry, a term often used to describe the dissolution of a gas into a liquid or solid.

Molecular geometry

Molecules have fixed equilibrium geometries—bond lengths and angles— about which they continuously oscillate through vibrational and rotational motions. A pure substance is composed of molecules with the same average geometrical structure. .The chemical formula and the structure of a molecule are the two important factors that determine its properties, particularly its reactivity.^ An important property in determining the particle surface area .

^ Elements in a group have similar chemical properties and formulas.

^ Hydrogen bonds are important in fixing properties such as solubilities, melting points, and boiling points, and in determining the form and stability of crystalline structures.
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.Isomers share a chemical formula but normally have very different properties because of their different structures.^ Elements in a group have similar chemical properties and formulas.

^ The reason for the word "periodic" is because as   elements increase in atomic number and atomic mass, similar chemical and physical   properties occur over and over.

^ It has the same chemical formula as glucose (the chief source of energy for living organisms) but has a different arrangement of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.Stereoisomers, a particular type of isomers, may have very similar physico-chemical properties and at the same time different biochemical activities.^ They therefore tend to have similar chemical properties.
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^ There are several types of multiple endocrine neoplasia syndrome, and patients with each type may develop different types of cancer.
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^ Specific biomarkers may be linked to particular types of cancer.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

Molecular spectroscopy

Molecular spectroscopy deals with the response (spectrum) of molecules interacting with probing signals of known energy (or frequency, according to Planck's formula). Molecules have quantized energy levels that can be analyzed by detecting the molecule's energy exchange through absorbance or emission.[7] .Spectroscopy does not generally refer to diffraction studies where particles such as neutrons, electrons, or high energy X-rays interact with a regular arrangement of molecules (as in a crystal).^ It is being studied in the treatment of cancer symptoms such as lack of energy, pain, swelling, and depression.
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^ Interactions occur when a real particle come close enough (as in high energy collision) for one or more of the virtual particles in the cloud to be absorbed by the other real particle.
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^ Mass spectroscopy techniques such as ICP-MS which are based on the mass/charge ratios of the neutrons and protons in the nucleus of the atom remain unaffected by the rearranged orbital electrons and are able to detect the ORMEs.

Theoretical aspects

.The study of molecules by molecular physics and theoretical chemistry is largely based on quantum mechanics and is essential for the understanding of the chemical bond.^ The transition from classical to quantum in theoretical physics is most elegantly prescribed by path integral.
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^ Followings are some basic concepts of inorganic chemistry: Periodic Table - A molecule is a compound composed of a group of two or more atoms held together by chemical bonds.
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^ When an atom or molecule combines with oxygen, it tends to give up electrons to the oxygen in forming a chemical bond .

.The simplest of molecules is the hydrogen molecule-ion, H2+, and the simplest of all the chemical bonds is the one-electron bond.^ Hydrogen with one valence electron forms a single covalent bond.
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^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
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^ This is because water molecules help form hydrogen bonds between DNA's phosphate groups.
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.H2+ is composed of two positively-charged protons and one negatively-charged electron, which means that the Schrödinger equation for the system can be solved more easily due to the lack of electron–electron repulsion.^ The negative charge results because there are more electrons than protons in the anion.

^ The charge results because there are more protons than electrons in the cation due to missing orbital electrons.

^ A neutral hadron that is stable in the atomic nucleus but decays into a proton , an electron , and antineutrino with a mean life of 12 minutes outside the nucleus.

.With the development of fast digital computers, approximate solutions for more complicated molecules became possible and are one of the main aspects of computational chemistry.^ The measurement of the conductivity of an electrolyte solution is more complicated than a similar measurement with a metallic conductor.

^ Molecules are made up of one or more atoms.
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^ If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.When trying to define rigorously whether an arrangement of atoms is "sufficiently stable" to be considered a molecule, IUPAC suggests that it "must correspond to a depression on the potential energy surface that is deep enough to confine at least one vibrational state".[1] This definition does not depend on the nature of the interaction between the atoms, but only on the strength of the interaction.^ Overall colloid stability depends on the interaction between individual particles.

^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ Whether the movement of the fluid is due to "forced" or "natural" convection, a thin layer of fluid will always remain completely immobile at the surface of the solid due to the solid-liquid interactive forces.

.In fact, it includes weakly-bound species that would not traditionally be considered molecules, such as the helium dimer, He2, which has one vibrational bound state[8] and is so loosely bound that it is only likely to be observed at very low temperatures.^ While the latter is linked to the oscillating state of the molecule, which occurs only at certain resonant energy so that the emitting or absorbing photon can carry only .
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^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ The former is related to the initial and final states of the molecule, which favors the one step change in the rotational configuration.
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See also

References

  1. ^ a b International Union of Pure and Applied Chemistry (1994). "molecule". Compendium of Chemical Terminology Internet edition.
  2. ^ Pauling, Linus (1970). General Chemistry. New York: Dover Publications, Inc.. ISBN 0-486-65622-5.  
    Ebbin, Darrell, D. (1990). General Chemistry, 3rd Ed.. Boston: Houghton Mifflin Co.. ISBN 0-395-43302-9.  
    Brown, T.L. (2003). Chemistry – the Central Science, 9th Ed.. New Jersey: Prentice Hall. ISBN 0-13-066997-0.  
    Chang, Raymond (1998). Chemistry, 6th Ed.. New York: McGraw Hill. ISBN 0-07-115221-0.  
    Zumdahl, Steven S. (1997). Chemistry, 4th ed.. Boston: Houghton Mifflin. ISBN 0-669-41794-7.  
  3. ^ Chandra, Sulekh. Comprehensive Inorganic Chemistry. New Age Publishers. ISBN 8122415121.  
  4. ^ Molecule Definition (Frostburg State University)
  5. ^ Chang RL, Deen WM, Robertson CR, Brenner BM. (Oct 1975). "Permselectivity of the glomerular capillary wall: III. Restricted transport of polyanions". Kidney Int. 8 (4): 212–218. PMID 1202253.  
  6. ^ Chang RL, Ueki IF, Troy JL, Deen WM, Robertson CR, Brenner BM. (Sept 1975). "Permselectivity of the glomerular capillary wall to macromolecules. II. Experimental studies in rats using neutral dextran". Biophys J. 15 (9): 887–906. PMID 1182263.  
  7. ^ International Union of Pure and Applied Chemistry (1997,2006). "spectroscopy". Compendium of Chemical Terminology Internet edition.
  8. ^ Anderson JB (May 2004). "Comment on "An exact quantum Monte Carlo calculation of the helium-helium intermolecular potential" [J. Chem. Phys. 115, 4546 (2001)]". J Chem Phys 120 (20): 9886–7. doi:10.1063/1.1704638. PMID 15268005.  

External links


1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

MOLECULE (from mod. Lat. .molecula, the diminutive of moles, a mass), in chemistry and physics, the minutest particle of matter capable of separate existence.^ Because of his (and others) work, we think of electrons both as particles of matter (having mass is a property of matter) and as units (or quanta) of energy.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

The word appears to have been invented during the 17th century, and remained synonymous with " atom " (Gr. &TOµos, from a-, privative, and TEµvEw, to cut) until the middle of the 19th century, when a differentiation was established. ." Atom " has mainly a chemical import, being defined as the smallest particle of matter which can take part in a chemical reaction; a " molecule " is composed of atoms, generally two or more.^ Atom with aSymbol chemical symbol to the molecule.

^ The smallest part of an element that can exist chemically.

^ A charge that an atom accepts in a chemical     reaction in the formation of a molecule.

.For the detailed chemical significance of these terms, see Chemistry; and for the atomic theory of the chemist (as distinguished from the atomic or molecular theory of the physicist) see Atom; reference may also be made to the article Matter.^ We now see what a molecule is, as distinguished from an atom.

^ Bohr's atom Bohr made significant contributions to the atom.
  • Chemistry Glossary 24 January 2010 16:37 UTC www.shodor.org [Source type: Reference]

^ Over the years, substantial changes have taken place regarding the atomic theory, yet some of the assumptions that Dalton made are still held valid.
  • Atoms and Molecules | TutorVista 24 January 2010 16:37 UTC www.tutorvista.com [Source type: Reference]

.The doctrine that matter can be divided into, or regarded as composed of, discrete particles (termed " atoms " by early writers, and " molecules " by modern ones) has at all times played an important part in metaphysics and natural science.^ Molecular Molecular substances are composed of discrete molecules.
  • Glossary 24 January 2010 16:37 UTC www.chem.wisc.edu [Source type: FILTERED WITH BAYES]

^ Atoms are the smallest particle into which an element can be divided.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ All forms of matter are composed of one or more elements.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

.The leading historical stages in the evolution of the modern conception of the molecular structure of matter are treated in the following passage from James Clerk Maxwell's article Atom in the 9th edition of the Ency.^ Network solids can not have an exact molecular formula since an undefined number of atoms are involved in each structure.
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^ James Clerk Maxwell .

^ Atoms and Molecules Laws of Chemical Combination The Atom Formation of Molecule Chemical Formulae Molecular Mass and Mole Concept Numericals Based on Mole Concept Summary Multiple Choice Questions .
  • Atoms and Molecules | TutorVista 24 January 2010 16:37 UTC www.tutorvista.com [Source type: Reference]

Brit. ."
Atom 1 (iiTopos) is a body which cannot be cut in two.^ An atom is a body which cannot be cut in two.

^ We should thus, in imagination, arrive at the atom, which, as its name literally signifies, cannot be cut in two.

^ The question of the existence or non-existence of atoms cannot be presented to us this evening with greater clearness than in the alternative theories of these two philosophers.

.The atomic theory is a theory of the constitution of bodies which asserts that they are made up of atoms.^ Atoms themselves are made up of smaller particles called protons, electrons, and neutrons.
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^ Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The molecules are conformed to a constant type with a precision which is not to be found in the sensible properties of the bodies which they constitute.

.The opposite theory is that of the homogeneity and continuity of bodies, and asserts, at least in the case of bodies having no apparent organization, such, for instance, as water, that as we can divide a drop of water into two parts which are each of them drops of water, so we have reason to believe that these smaller drops can be divided again, and the theory goes on to assert that there is nothing in the nature of things to hinder this process of division from being repeated over and over again, times without end.^ The process a cell goes through each time it divides.
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^ In medicine, having to do with the movement of body parts.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Hence if the whole drop is divisible, so are its parts down to the minutest sub-divisions, and that without end.

.This is the doctrine of the infinite divisibility of bodies, and it is in direct contradiction with the theory of atoms.^ The doctrine of atoms and that of homogeneity are thus in direct contradiction.

^ Do atoms exist, or is matter infinitely divisible?

." The atomists assert that after a certain number of such divisions the parts would be no longer divisible, because each of them would be an atom.^ It was postulated that the momentum p and position q are no longer mere numbers but are operators satisfying the commutative relation: (qp - pq) = i .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ A drop of water, to return to our former example, may be divided into a certain number, and no more, of portions similar to each other.

.The advocates of the continuity of matter assert that the smallest conceivable body has parts, and that whatever has parts may be divided.^ A microfluidic device may use body fluids or solutions containing cells or cell parts to diagnose diseases.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

." In ancient times Democritus was the founder of the atomic theory, while Anaxagoras propounded that of continuity, under the name of the doctrine of homoeomeria ('OAotop.pia), or of the similarity of the parts of a body to the whole.^ The essence of the doctrine of Anaxagoras is that the parts of a body are in all respects similar to the whole.

^ According to Anaxagoras, on the other hand, the parts into which the drop is divided, are in all respects similar to the whole drop, the mere size of a body counting for nothing as regards the nature of its substance.

^ No theory of evolution can be formed to account for the similarity of molecules, for evolution necessarily implies continuous change, and the molecule is incapable of growth or decay, of generation or destruction.

The arguments of the atomists, and their replies to the objections of Anaxagoras, are to be found in Lucretius.
." In modern times the study of nature has brought to light many properties of bodies which appear to depend on the magnitude and motions of their ultimate constituents, and the question of the existence of atoms has once more become conspicuous among scientific inquiries.^ It leaves him in possession of methods which nothing but scientific work could have led him to invent, and it places him in a position from which many regions of nature, besides that which he has been studying, appear under a new aspect.

^ None of the processes of Nature, since the time when Nature began, have produced the slightest difference in the properties of any molecule.

^ Recently in 2006, the Nature magazine asked many leading chemists what are the field's big questions.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

" We shall begin by stating the opposing doctrines of atoms and of continuity. .The most ancient philosophers whose speculations are known to us seem to have discussed the ideas of number and of continuous magnitude, of space and time, of matter and motion, with a native power of thought which has probably never been surpassed.^ The uncertainty in space and time is interpreted as the probability of finding the particle at a certain time and place.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ We have no time to do more than mention that most wonderful molecular motion which is called electrolysis.

^ Clausius, of Bonn, who first gave us precise ideas about the motion of agitation of molecules, calls this distance the mean path of a molecule.

.Their actual knowledge, however, and their scientific experience were necessarily limited, because in their days the records of human thought were only beginning to accumulate.^ The total human body content of ATP is only about 50 grams, which must be constantly recycled every day.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

^ Without care for the scientific fundamentals, confused thought is likely to prevent advances in scientific knowledge and to lead to bad legislation and to generally bad decision-making.

It is probable that the first exact notions of quantity were founded on the consideration of number. .It is by the help of numbers that concrete quantities are practically measured and calculated.^ The mean is calculated by adding all of the data values and dividing this quantity by the total number of data values.

Now, number is discontinuous. .We pass from one number to the next per saltum. The magnitudes, on the other hand, which we meet with in geometry, are essentially continuous.^ Atoms of one type of element differ from those of the other due to different number of sub-atomic particles.
  • Atoms and Molecules | TutorVista 24 January 2010 16:37 UTC www.tutorvista.com [Source type: Reference]

^ Here is an electric current passing through acidulated water, and causing oxygen to appear at one electrode and hydrogen at the other.

^ But in tracing back the history of matter Science is arrested when she assures herself, on the one hand, that the molecule has been made, and on the other that it has not been made by any of the processes we call natural.

.The attempt to apply numerical methods to the comparison of geometrical quantities led to the doctrine of incommensurables, and to that of the infinite divisibility of space.^ The data of the statistical method as applied to molecular science are the sums of large numbers of molecular quantities.

.Meanwhile, the same considerations had not been applied to time, so that in the days of Zeno of Elea time was still regarded as made up of a finite number of ` moments,' while space was confessed to be divisible without limit.^ Over the years, substantial changes have taken place regarding the atomic theory, yet some of the assumptions that Dalton made are still held valid.
  • Atoms and Molecules | TutorVista 24 January 2010 16:37 UTC www.tutorvista.com [Source type: Reference]

^ Payment through POSB bank transfer and must be made within 2 days, item will be release for sale without further notice if payment is not received on time.

^ At the same time, legal regulations often specify a list of heavy metals to which they apply.

.This was the state of opinion when the celebrated arguments against the possibility of motion, of which that of Achilles and the tortoise is a specimen, were propounded by Zeno, and such, apparently, continued to be the state of opinion till Aristotle pointed out that time is divisible without limit, in precisely the same sense that space is.^ Thus each molecule is continually getting its course altered, so that in spite of its great velocity it may be a long time before it reaches any great distance from the point at which it set out.

^ From there on out, the cell will maintain the same number and species of chromosomes in subsequent divisions.

^ Since it implies that p cannot be a function of q (because it would mean p and q can be determined precisely at the same time), p can be related to q only in the form of an operator such as - i d/dq, where i = .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.And the slowness of the development of scientific ideas may be estimated from the fact that Bayle does not see any force in this statement of Aristotle, but continues to admire the paradox of Zeno (Bayle's Dictionary, art.^ CSL is equipped with state of the art scientific equipment specifically developed for characterizing colloidal solutions.

^ The further development of the theory is generally supposed to have been begun with a paper by Krönig, which does not, however, so far as I can see, contain any improvement on what had gone before.

^ One may see the atom as a material point, invested and surrounded by potential forces.

` Zeno '). Thus the direction of true scientific progress was for many ages towards the recognition of the infinite divisibility of space and time.
" It was easy to attempt to apply similar arguments to matter. .If matter is extended and fills space, the same mental operation by which we recognize the divisibility of space may be applied, in imagination at least, to the matter which occupies space.^ Matter has mass and occupies space.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ Conditions that serve to sustain one cell type may not apply to other cell types, or even the same cell type from another species.

.From this point of view the atomic doctrine might be regarded as a relic of the old numerical way of conceiving magnitude, and the opposite doctrine of the infinite divisibility of matter might appear for a time the most scientific.^ Do atoms exist, or is matter infinitely divisible?

^ Most of the phenomena were described originally from the macroscopic point of view.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ But these astronomical and terrestrial magnitudes are far inferior in scientific importance to that most fundamental of all standards which forms the base of the molecular system.

.The atomists, on the other hand, asserted very strongly the distinction between matter and space.^ This procedure takes advantage of a special property of nitrocellulose, its ability to bind very strongly to single-stranded DNA but not double-stranded DNA. On the other hand, Northern blotting refers to any blotting procedure in which electrophoresis is performed using RNA. .

^ But in tracing back the history of matter Science is arrested when she assures herself, on the one hand, that the molecule has been made, and on the other that it has not been made by any of the processes we call natural.

.The atoms, they said, do not fill up the universe; there are void spaces between them.^ Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ DNA and RNA (Access Excellence) Monosaccharide Browser (Leeds University, UK) View space-filling models of a variety of monosaccahrides.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ For example, the de Broglie wavelength for a 75 ev electron is 2 x 10 -8 cm, thus the spacing between atoms in a crystal is a good diffraction grating for such electron.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.If it were not so, Lucretius tells us, there could be no motion, for the atom which gives way first must have some empty place to move into.^ Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond.
  • CHEMISTRY I: ATOMS AND MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ The subscript tells us   how Mother Nature put atoms together to make molecules.

^ The number in front of an atom or a molecule to tell how many there     are of each kind.

` Quapropter locus est intactus, inane, vacansque Q uod si non esset, nulla ratione moveri Res possent; namque, officium quod corporis exstat, Officere atque obstare, id in omni tempore adesset Omnibus: haud igitur quicquam procedere posset, Principium quoniam cedendi nulla daret res.' De rerum natura, i. 335.
." The opposite school maintained then, as they have always done, 1 It wiII be noted that Clerk Maxwell's " atom " and " atomic theory " have the significance which we now attach to " molecule " and " molecular theory."^ We now see what a molecule is, as distinguished from an atom.

^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Now that scientists understand how some of these highly organized molecules function and why they are required for life, their origin must be explained.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

that there is no vacuum - that every part of space is full of matter, that there is a universal plenum, and that all motion is like that of a fish in the water, which yields in front of the fish because the fish leaves room for it behind.
' Cedere squamigeris latices nitentibus aiunt Et liquidas aperire vias, quia post loca pisces Linquant, quo possint cedentes confluere undae.' Ibid. i. 373.
" In modern times Descartes held that, as it is of the essence of matter to be extended in length, breadth and thickness, so it is of the essence of extension to be occupied by matter, for extension cannot be an extension of nothing.
" ' Ac proinde si quaeratur quid fiet, si Deus auferat omne corpus quod in aliquo vase continetur, et nullum aliud in ablati locum venire permittat? respondendum est, oasis latera sibi invicem hoc ipso fore contigua. Cum enim inter duo corpora nihil interjacet, necesse est ut se mutuo tangant, ac manifeste repugnat ut distent, sive ut inter ipsa sit distantia, et tamen ut ista distantia sit nihil; quia omnis distantia est modus extensionis, et ideo sine substantia extensa esse non potest.' - Principia, ii. 18.
." This identification of extension with substance runs through the whole of Descartes's works, and it forms one of the ultimate foundations of the system of Spinoza.^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ In traditional Chinese medicine, one of 20 channels that form a network through which qi (the body's vital energy) flows and that connect the body’s acupuncture sites.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ In liquids and gases, however, the molecules are not confined within any definite limits, but work their way through the whole mass, even when that mass is not disturbed by any visible motion.

.Descartes, consistently with this doctrine, denies the existence of atoms as parts of matter, which by their own nature are indivisible.^ Water Water is a major constituent of all living matter consisting of two parts hydrogen and one part oxygen.

.He seems to admit, however, that the Deity might make certain particles of matter indivisible in this sense, that no creature should be able to divide them.^ A drop of water, to return to our former example, may be divided into a certain number, and no more, of portions similar to each other.

^ Still we have no doubt that the sub-division might be carried further, if our senses were more acute and our instruments more delicate.

^ But that there should be exactly so much matter and no more in every molecule of hydrogen is a fact of a very different order.

.These particles, however, would be still divisible by their own nature, because the Deity cannot diminish his own power, and therefore must retain his power of dividing them.^ Because of the large size of the silver particles these products have very low particle surface area .

^ When scientists started exploring matter, they realised that matter can be divided into smaller and still smaller particles.
  • Atoms and Molecules | TutorVista 24 January 2010 16:37 UTC www.tutorvista.com [Source type: Reference]

^ We have reached the utmost limit of our thinking faculties when we have admitted that because matter cannot be eternal and self-existent it must have been created.

Leibniz, on the other hand, regarded his monad as the ultimate element of everything.
." There are thus two modes of thinking about the constitution of bodies, which have had their adherents both in ancient and in modern times.^ Every time that two molecules come into collision, the paths of both are changed, and they go off in new directions.

^ The old atomic theory, as described by Lucretius and revived in modern times, asserts that the molecules of all bodies are in motion, even when the body itself appears to be at rest.

They correspond to the two methods of regarding quantity - the arithmetical and the geometrical. To the atomist the true method of estimating the quantity of matter in a body is to count the atoms of it. .The void spaces between the atoms count for nothing.^ For example, the de Broglie wavelength for a 75 ev electron is 2 x 10 -8 cm, thus the spacing between atoms in a crystal is a good diffraction grating for such electron.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.To those who identify matter with extension, the volume of space occupied by a body is the only measure of the quantity of matter in it.^ Pamela: Now to get those pints however, what size volume of Space are you probing?
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

" Of the different forms of the atomic theory that of R. J. Boscovich may be taken as an example of the purest monadism. .According to Boscovich matter is made up of atoms.^ Elements are made up of atoms of only one kind.

^ Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Molecules are made up of one or more atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.Each atom is an indivisible point, having position in space, capable of motion in a continuous path, and possessing a certain mass, whereby a certain amount of force is required to produce a given change of motion.^ Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ That matter, as such, should have certain fundamental properties — that it should exist in space and be capable of motion, that its motion should be persistent, and so on, are truths which may, for anything we know, be of the kind which metaphysicians call necessary.

^ The amount of energy required to break a bond and produce neutral atoms is called the bond energy.

.Besides this the atom is endowed with potential force, that is to say, that any two atoms attract or repel each other with a force depending on their distance apart.^ In other words, the equilibrium electrode potential difference between the two electrodes of the cell.

^ When the distance separating individual atoms is only a few atomic diameters, the force of attraction can exceed 100,000 G-forces.

^ The atoms in a silver particle remain held together by van der Waals’ force of attraction that causes like (identical) atoms to be attracted to each other.

.The law of this force, for all distances greater than say the thousandth of an inch, is an attraction varying as the inverse square of the distance.^ When the distance separating individual atoms is only a few atomic diameters, the force of attraction can exceed 100,000 G-forces.

^ All bonds arise from the attraction of unlike charges according to Coulomb's law; however, depending on the atoms involved, this force manifests itself in quite different ways.

^ On a molecule in the surface, however, there is a resultant attraction inwards, because the number of molecules is greater in the bulk of the liquid than in the vapor.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.For smaller distances the force is an attraction for one distance and a repulsion for another, according to some law not yet discovered.^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ When the distance separating individual atoms is only a few atomic diameters, the force of attraction can exceed 100,000 G-forces.

^ A dipole will align itself, if possible, in the presence of other electrical charges according to the attraction of opposite and repulsion of like charges.

.Boscovich himself, in order to obviate the possibility of two atoms ever being in the same place, asserts that the ultimate force is a repulsion which increases without limit as the distance diminishes without limit, so that two atoms can never coincide.^ The angle subtended by the two hydrogen atoms then increase from 105 to 109 degrees resulting a less tightly packed configuration (Figure 12-16b).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Generally, ATP is connected to another reaction—a process called coupling which means the two reactions occur at the same time and at the same place, usually utilizing the same enzyme complex.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

^ If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.But this seems an unwarrantable concession to the vulgar opinion that two bodies cannot co-exist in the same place.^ Also, back-up mechanisms sometimes exist so that the body can achieve the same goals through an alternative biochemical route.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

^ Generally, ATP is connected to another reaction—a process called coupling which means the two reactions occur at the same time and at the same place, usually utilizing the same enzyme complex.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

This opinion is deduced from our experience of the behaviour of bodies of sensible size, but we have no experimental evidence that two atoms may not sometimes coincide. .For instance, if oxygen and hydrogen combine to form water, we have no experimental evidence that the molecule of oxygen is not in the very same place with the two molecules of hydrogen.^ According to the received doctrine, in each molecule of water there are two molecules of hydrogen and one of oxygen.

^ Take two litres of any specimen of hydrogen, it will combine with exactly one litre of any specimen of oxygen, and will form exactly two litres of the vapour of water.

^ The ATP synthase revolving door resembles a molecular water wheel that harnesses the flow of hydrogen ions in order to build ATP molecules.
  • ATP: The Perfect Energy Currency for the Cell 24 January 2010 16:37 UTC www.trueorigin.org [Source type: Academic]

.Many persons cannot get rid of the opinion that all matter is extended in length, breadth and depth.^ This is because not all restriction sites will exist within everyone's DNA. These variations in fragment length are referred to as restriction fragment length polymorphisms (RFLPs) , and the pattern of fragments is unique for each person.

This is a prejudice of the same kind with the last, arising from our experience of bodies consisting of immense multitudes of atoms. .The system of atoms, according to Boscovich, occupies a certain region of space in virtue of the forces acting between the component atoms of the system and any other atoms when brought near them.^ The alkenes contain a functional group that is a double bond between two adjacent carbon atoms; one of these bond can be linked to other atoms.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ It is also used in plant microscopy anatomy studies, because it fluoresces under ultraviolet light and stains certain regions between plant cells.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

^ For example, the de Broglie wavelength for a 75 ev electron is 2 x 10 -8 cm, thus the spacing between atoms in a crystal is a good diffraction grating for such electron.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.No other system of atoms can occupy the same region of space at the same time, because before it could do so the mutual action of the atoms would have caused a repulsion between the two systems insuperable by any force which we can command.^ Since the ring is too small to accommodate two double bonds to the same carbon atom, the position numbers of 1 and 3 are often dropped from the name, since there is no other set of position numbers possible for the ring.
  • Molecule Gallery - Alkenes 24 January 2010 16:37 UTC www.angelo.edu [Source type: Reference]

^ In other words, the equilibrium electrode potential difference between the two electrodes of the cell.

^ According to his theory each quantum event would create its own distortions in space-time, which requires energy to sustain.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.Thus, a number of soldiers with firearms may occupy an extensive region to the exclusion of the enemy's armies, though the space filled by their bodies is but small.^ Small numbers of cancer cells that have spread from the primary tumor to other parts of the body and are too few to be picked up in a screening or diagnostic test.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

In this way Boscovich explained the apparent extension of bodies consisting of atoms, each of which is devoid of extension. According to Boscovich's theory, all action between bodies is action at a distance. .There is no such thing in nature as actual contact between two bodies.^ However, in electrochemistry "emf" usually refers to the potential difference between the two electrodes of an electrochemical cell when there is no current flowing through the cell, "voltage" refers to same with current flowing, and "potential" is usually used in connection with electrodes .

^ There is no > chemistry anywhere near your assertion short of two-photon transitions > - that have a quadratic dependence upon illumination intensity.
  • Here's a twist, using water as a UV shield for other molecules - sci.astro | Google Groups 24 January 2010 16:37 UTC groups.google.com [Source type: FILTERED WITH BAYES]

^ There are number of natural polymers, such as polysaccharides.

.When two bodies are said in ordinary language to be in contact, all that is meant is that they are so near together that the repulsion between the nearest pairs of atoms belonging to the two bodies is very great.^ Atoms are called monovalent, divalent, trivalent, or tetravalent, according to whether they form one, two, three, or four bonds (see chemical bond ).

^ The solid line denotes a bond with two sharing electrons in between the atoms, while the dot represents the electron not in a bond.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Although atoms are neutral, they become charged in chemical reactions that start   when atoms are heated, struck, hit, or in close contact with other atoms.

" Thus, in Boscovich's theory, the atom has continuity of existence in time and space. .At any instant of time it is at some point of space, and it is never in more than one place at a time.^ They have more than one valence.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ A clinical trial that is carried out at more than one medical institution.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

It passes from one place to another along a continuous path. It has a definite mass which cannot be increased or diminished. .Atoms are endowed with the power of acting on one another by attraction or repulsion, the amount of the force depending on the distance between them.^ When the distance separating individual atoms is only a few atomic diameters, the force of attraction can exceed 100,000 G-forces.

^ The atoms in a silver particle remain held together by van der Waals’ force of attraction that causes like (identical) atoms to be attracted to each other.

^ All bonds arise from the attraction of unlike charges according to Coulomb's law; however, depending on the atoms involved, this force manifests itself in quite different ways.

On the other hand, the atom itself has no parts or dimensions. In its geometrical aspect it is a mere geometrical point. It has no extension in space. .It has not the so-called property, of Impenetrability, for two atoms may exist in the same place.^ Atoms are called monovalent, divalent, trivalent, or tetravalent, according to whether they form one, two, three, or four bonds (see chemical bond ).

^ Propadiene is an example of an allene , in which there are two double bonds to the same carbon atom.
  • Molecule Gallery - Alkenes 24 January 2010 16:37 UTC www.angelo.edu [Source type: Reference]

^ In an element, all the atoms have the same number of protons and electrons , although the number of neutrons may vary.

This we may regard as one extreme of the various opinions about the constitution of bodies.
" The opposite extreme, that of Anaxagoras - the theory that bodies apparently homogeneous and continuous are so in reality - is, in its extreme form, a theory incapable of development. To explain the properties of any substance by this theory is impossible. .We can only admit the observed properties of such substance as ultimate facts.^ A substance, such as a detergent, added to a liquid to increase its spreading or wetting properties by reducing its surface tension.

.There is a certain stage, however, of scientific progress in which a method corresponding to this theory is of service.^ However, within this vast number of compounds, there are characteristic structural features called functional groups , which are a certain group of atoms that react in a predictable way.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.In hydrostatics, for instance, we define a fluid by means of one of its known properties, and from this definition we make the system of deductions which constitutes the science of hydrostatics.^ The more general statement reads: At the quantum level, the most general physical properties of any system must be expressed in terms of complementary pairs of variables, each of which can be better defined only at the expense of a corresponding loss in the degree of definition of the other.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ These well-defined properties, which quantum mechanics does not describe, are known as "hidden variables".
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Ancient Indian medical system meaning 'science of life'.
  • AMFI - Molecules of Emotion: Resources 24 January 2010 16:37 UTC www.amfoundation.org [Source type: Academic]

In this way the science of hydrostatics may be built upon an experimental basis, without any consideration of the constitution of a fluid as to whether it is molecular or continuous. .In like manner, after the French mathematicians had attempted, with more or less ingenuity, to construct a theory of elastic solids from the hypothesis that they consist of atoms in equilibrium under the action of their mutual forces, Stokes and others showed that all the results of this hypothesis, so far at least as they agreed with facts, might be deduced from the postulate that elastic bodies exist, and from the hypothesis that the smallest portions into which we can divide them are sensibly homogeneous.^ The user can then select the molecule (or a portion of it), copy it to the clipboard, and insert it into the model they are working on.
  • Molecules 2.02 | Vensim 24 January 2010 16:37 UTC www.vensim.com [Source type: FILTERED WITH BAYES]

^ They are also called saturated hydrocarbons because they cannot add any more hydrogen atoms to the structure.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ The atoms in a silver particle remain held together by van der Waals’ force of attraction that causes like (identical) atoms to be attracted to each other.

In this way the principle of continuity, which is the basis of the method of Fluxions and the whole of modern mathematics, may be applied to the analysis of problems connected with material bodies by assuming them, for the purpose of this analysis, to be homogeneous. .All that is required to make the results applicable to the real case is that the smallest portions of the substance of which we take any notice shall be sensibly of the same kind.^ The smallest particle of a substance that has all of the physical and chemical properties of that substance.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Comparing his results with those of Loschmidt on gases, we find that about as much diffusion takes place in a second in gases as requires a day in liquids.

^ In the second place the properties of all molecules of the same kind are absolutely identical.

.Thus, if a railway contractor has to make a tunnel through a hill of gravel., and if one cubic yard of the gravel is so like another cubic yard that for the purposes of the contract they may be taken as equivalent, then, in estimating the work required to remove the gravel from the tunnel, he may, without fear of error, make his calculations as if the gravel were a continuous substance.^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ This potential difference cannot be measured because there is no way to make an electrical connection to the solution phase without setting up another electrode potential.

^ They can also be filled with a substance that may help kill more tumor cells.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.But if a worm has to make his way through the gravel, it makes the greatest possible difference to him whether he tries to push right against a piece of gravel, or directs his course through one of the intervals between the pieces; to him, therefore, the gravel is by no means a homogeneous and continuous substance.^ Only because the molecules happen to be flying in different directions, so that those which strike against our backs enable us to support the storm which is beating against our faces.

^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ When we look to see which slit the electron goes through, we make one world real while the other disappears, so there is no interference (see single slit pattern in Figure 12-06f).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

." In the same way, a theory that some particular substance, say water, is homogeneous and continuous may be a good working theory up to a certain point, but may fail when we come to deal with quantities so minute or so attenuated that their heterogeneity of structure comes into prominence.^ Solution - Water is a good solvent able to dissolve many polar substances (Figure 12-16c).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Thus each molecule is continually getting its course altered, so that in spite of its great velocity it may be a long time before it reaches any great distance from the point at which it set out.

^ For example, a researcher may test the cells' ability to metabolize a particular substance or study traits of antibiotic resistance.

Whether this heterogeneity of structure is or is not consistent with homogeneity and continuity of substance is another question.
." The extreme form of the doctrine of continuity is that stated by Descartes, who maintains that the whole universe is equally full of matter, and that this matter is all of one kind, having no essential property besides that of extension.^ Therefore, no matter how far apart are the members of this pair, if the spin is flipped for one of the member, the spin for the other member will also be flipped to the opposite at precisely the same moment.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ ORMEs were discovered by David Hudson who holds worldwide patents on eleven ORMEs which represent a new form of matter.

^ Mathematically, the property of superposition of states is directly related to the special form of linear differential equation , which governs the behaviour of a single particle in quantum theory.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.All the properties which we perceive in matter he reduces to its parts being movable among one another, and so capable of all the varieties which we can perceive to follow from the motion of its parts (Principia, ii.^ To spread from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The spread of cancer from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Breast cancer in which there is more than one tumor, all of which have formed separately from one another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

23). Descartes's own attempts to deduce the different qualities and actions of bodies in this way are not of much value. .More than a century was required to invent methods of investigating the conditions of the motion of systems of bodies such as Descartes imagined.^ It has a pleasant cooling taste, since it causes the cold receptors on the tongue to activate at higher temperatures than normal (such as body temperature).
  • Molecule Gallery - Alkenes 24 January 2010 16:37 UTC www.angelo.edu [Source type: Reference]

^ The Schrodinger Equation can be expanded to a system of many particles and more than one source of interaction.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ For large-scale DNA analysis methods, such as those required to sequence the human genome, DNA isolation is performed using robots.

But the hydrodynamical discovery of Helmholtz that a vortex in a perfect liquid possesses certain permanent characteristics has been applied by Sir W. Thomson (Lord Kelvin) to form a theory of vortex atoms in a homogeneous, incompressible and frictionless liquid." THE Molecular Structure Of Matter An enormous mass of experimental evidence now shows quite conclusively that matter cannot be regarded as having a continuous structure, but that it is ultimately composed of discrete parts. .The smallest unit of matter with which physical phenomena are concerned is the molecule. When chemical phenomena occur the molecule may be divided into atoms, and these atoms, in the presence of electrical phenomena, may themselves be further divided into electrons or corpuscles. It ought accordingly to be possible to explain all the non-electrical and non-chemical properties of matter by treating matter as an aggregation of molecules.^ The smallest particle of a substance that has all of the physical and chemical properties of that substance.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ An atom is the smallest particle of an      element with the properties of that element.

^ The outermost electrons of an atom determine its chemical and electrical properties.

.In point of fact it is found that the properties which are most easily explained are those connected with the gaseous state; the explanation of these properties in terms of the molecular structure of matter is the aim of the " Kinetic Theory of Gases."^ Hydrogen bonds are important in fixing properties such as solubilities, melting points, and boiling points, and in determining the form and stability of crystalline structures.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Mathematically, the property of superposition of states is directly related to the special form of linear differential equation , which governs the behaviour of a single particle in quantum theory.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Electrochemistry - For the subject of physical chemistry the most important conductors are those of the electrolytes; they are distinguished from electronic conductors, such as metals, by the fact that the passage of an electric current is accompanied by the transfer of matter.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.The results of this theory have placed the molecular conception of matter in an indisputable position, but even without this theory there is such an accumulation of electrical and optical evidence in favour of the molecular conception of matter that the tenability of this conception could not be regarded as open to question.^ This potential difference cannot be measured because there is no way to make an electrical connection to the solution phase without setting up another electrode potential.

^ Such wave-particle duality requires radical changes in the fundamental concepts of the properties of matter and energy.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ The term "blotting" describes the overlaying of the membrane on the gel and the application of a pad to ensure even contact, without disturbing the positions of the DNA fragments.

The Scale of Molecular Structure

.Apart from speculation, the first definite evidence for the molecular structure of matter occurs when it is found that certain physical phenomena change their whole nature as soon as we deal with matter of which the linear dimensions are less than a certain amount.^ A higher-than-normal amount of mesothelin is found on some cancer cells, including mesothelioma, pancreatic cancer, and ovarian cancer.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Go To Top U Ubiquinone Ubiquinone is a naturally occurring coenzyme found in the mitochondria of the heart, liver, kidneys, and pancreas.

^ In addition to essential oils, terpenes and terpenoids are also found in naturally occurring dyes.
  • Molecule Gallery - Alkenes 24 January 2010 16:37 UTC www.angelo.edu [Source type: Reference]

As a single instance of this may be mentioned some experiments of Lord Rayleigh (Proc. Roy. Soc., 1890, 47, p. .364), who found that a film of olive oil spread over the surface of water produced a perceptible effect on small floating pieces of camphor, at places at which the thickness of the film was io 6 X10 -8 cms., but produced no perceptible effect at all at places where the thickness of the film was 8.1 X10 -8 cms.^ If the solution contained all ions and no particles, it would be considered an ionic solution, not a colloid since there would be no particles suspended in the water.

^ As a result, the surface tensions decreased and the water spreads .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Squalene is found in shark liver oil, and is also a major component of the lipids on the surface of human skin.
  • Molecule Gallery - Alkenes 24 January 2010 16:37 UTC www.angelo.edu [Source type: Reference]

.Thus a certain phenomenon, of the nature of capillary action, is seen to depend for its existence on the linear dimensions of the film of oil; the physical properties of a film of thickness Io 6Xio 8 cms.^ Thus an element in a certain position in a group   (the vertical column) has similar properties as all of the other elements in the   same group even though they are in a different period or row.

are found to be in some way qualitatively different from those of a film of thickness 8.1 X io 8 cms. .Here is proof that the film of oil is not a continuous homogeneous structure, and we are led to suspect that the scale on which the structure is formed has a unit of length comparable with 8 X10 -8 cms.^ The unit of conductivity is Siemens/m or in scaled form Siemens/cm.

The probability of this conjecture is strengthened when it is discovered that in all phenomena of this type the critical length connected with the stage at which the phenomenon changes its nature is of the order of magnitude of 10 -8 cms.
Lord Rayleigh (Phil. Mag. 18 9 0 [5], 3 0, p. .474) has pointed out that the earliest known attempt to estimate the size of molecules, made by Thomas Young in 1805, was based upon the consideration of phenomena of the kind just mentioned.^ Molecules made up of H and C are known as hydrocarbons.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ Because a scientist always loads and runs a "control" sample that contains multiple fragments of DNA with known sizes, the sizes of the sample DNA fragments can be estimated by comparing the control and sample bands.

^ One kind are particles produced out of the vacuum as mentioned above.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.Discussing the theory of capillary attractions, Young' found that at a rough estimate " the extent of the cohesive force must be limited to about the 250-millionth of an inch " (=10 8 cms.^ A particle 1 nm in diameter consists of 31 silver atoms, a particle 10 nm in diameter consists of about 31000 atoms and a particle 20 nm in diameter consists of about 250,000 atoms.

), and then argues that ." within similar limits of uncertainty we may obtain something like a conjectural estimate of the mutual distance of the particles of vapours, and even of the actual magnitude of the elementary atoms of liquids..^ Even things like Ethanol – a Molecule I AM very interested in [Laughter] – which may be familiar to some of your listeners.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ An elementary particle the is stable, bears a positive charge equal to an in magnitude to that of the electron , and has a mass of 1.672614 X 10 -27 kg, which is 1836.12 time that of an electron.

.. .It appears tolerably safe to conclude that, whatever errors 'may have affected the determination, the diameter or distance of the particles of water is between the two thousand and the ten thousand millionth of an inch " (= between 125 X I o 8 and 025 X 10 -8 cms.^ A particle 1 nm in diameter consists of 31 silver atoms, a particle 10 nm in diameter consists of about 31000 atoms and a particle 20 nm in diameter consists of about 250,000 atoms.

^ The mean diameter is determined from the volume analysis of the Particle Size Report generated by the Malvern Photon Correlation Spectrometer.

^ Usually this relies on the force of gravity, but if the particles are too small or the difference between the solid and liquid phase is too small, a centrifuge may be used.

).
The best estimates which we now possess of the sizes of molecules are provided by calculations based upon the kinetic theory of gases. .In the following table are given the values of the diameters of the molecules of six substances with which it is easy to experiment in the gaseous state, these values being calculated in different ways from formulae supplied by the kinetic theory.^ Isomers are molecules with identical molecular formulas but differ in arrangement of their atoms (e.g., glyceraldehyde and dihydroxyacetone).
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ These enzymes can cut DNA in two different ways.

^ Therefore nonanone becomes 'nonanon', and is quite an exceptional molecule name, being spelled the same way forwards and backwards - a palindromic molecule!
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

.The agreement of the values obtained for the same quantity by different methods provides valuable confirmation of the truth of the molecular theory and of the validity of the methods of the kinetic theory of gases.^ The first difference is that whereas classical theory always deals with continuously varying quantities, quantum theory must also deal with discontinuous or indivisible processes (e.g., the unit of energy packed in a quantum).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Because a measurement gives the conductance, methods have been devised to convert the measured value to the conductivity, so that results can be compared from different experiments.

That the results do not agree even 1 " On the Cohesions of Fluids," Phil. Trans. (1805); Young's Coll. Works, i. 461.
better need not cause surprise when it is stated that the quantities are calculated on the hypothesis that the molecules are spherical in shape. This hypothesis is introduced for the sake of simplicity, but is known to be unjustifiable in fact. .What is given by the formulae is accordingly the mean radius of an irregularly shaped solid (or, more probably, of the region in which the field of force surrounding such a solid is above a certain intensity), and the mean has to be taken in different ways in the different phenomena.^ Usually this relies on the force of gravity, but if the particles are too small or the difference between the solid and liquid phase is too small, a centrifuge may be used.

^ A change that occurs in the DNA of certain cells (such as tumor cells) in which the number of repeats of microsatellites (short, repeated sequences of DNA) is different than the number of repeats that was in the DNA when it was inherited.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The rate of migration of the particles depends on the field, the charge on the particles, and on other factors such as the size and shape of the particles.

.This and the difficulty of obtaining accurate experimental results fully account for the differences inter se in the values of the quantities calculated.^ Because a measurement gives the conductance, methods have been devised to convert the measured value to the conductivity, so that results can be compared from different experiments.

Heat a Manifestation of Molecular Motion

.An essential feature of the modern view of the structure of matter is that the molecules are supposed to be in rapid motion relatively to one another.^ Diagram (e) depicts the structural formula, which shows how the atoms in a molecule are bonded together in two dimensions, (f) is the chemical formula in one dimension showing just the .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

We are led to this conception by a number of experimental results, some of which will be mentioned later. We are compelled also to suppose that the motion assumes. different forms in different substances. .Roughly speaking, it is found that there are three main types of molecular motion corresponding to the three states of matter - solid, liquid and gaseous.^ There are several main types of malignancy.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Strictly speaking, there can be a small change in the potential of these electrodes depending on the electrolyte because the presence of a liquid-junction potential.

^ When solids or liquids form solutions, there must be an attraction between the solute particles and the solvent particles.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.That the distances traversed by the molecules of a solid are very small in extent is shown by innumerable facts of everyday observation, as for instance, the fact that the surface of a finely-carved metal (such as a plate used for steel engraving) will retain its exact shape for centuries, or again, the fact that when a metal body is coated with gold-leaf the molecules of the gold remain on its surface indefinitely: if they moved through.^ Whether the movement of the fluid is due to "forced" or "natural" convection, a thin layer of fluid will always remain completely immobile at the surface of the solid due to the solid-liquid interactive forces.

^ In fact, dinile is another name for butanedinitrile or succinonitrile, and is a waxy solid that if ingested forms cyanides in the body.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

^ Usually this relies on the force of gravity, but if the particles are too small or the difference between the solid and liquid phase is too small, a centrifuge may be used.

any but the smallest distances they would soon become mixed with the molecules of the baser metal and diffused through its interior. Thus the molecules of a solid must make only small excursions about their mean positions. .In a gas the state of things is very different; an odour is known to spread rapidly through great distances, even in the stillest air, and a gaseous poison or corrosive will attack not only those objects which are in contact with its source but also all those which can be reached by the motion of its molecules.^ All atoms and molecules -- even inert-gas such as those of helium and argon -- exhibit weak, short-range attractions for one another due to van der Waals forces.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Organic molecules are those that: 1) formed by the actions of living things; and/or 2) have a carbon backbone.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ The hotter the gas the faster those motions the harder it is for Gravity to get anything to collapse.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

Diameter calculated by the kinetic theory of gases.
Gas.
From devia-
tions from
From co-
efficient of
From co-
efficient of
conduction of
From co-
efficient of
Mean value.
Boyle's law.
viscosity.
heat.
diffusion.
Hydrogen
2 05Xio-8
2.05X10- 8
1.99X10- 8
2 02XIO- 8
2 03Xio-8
Carbon
monoxide
-
2.90 X o- 8
2.74 X I o- 8
2.92 X10- 8
2.85 X I o-8
Nitrogen .
3.12 X I o- 8
2.90 X 10- 8
2.74 X 10- 8
-
2.92 X10-8
Air. .
2.90Xio- 8
2.86XIo- 8
2.72X10- 8
-
2.83XIo-8
Oxyge
-
2.81 X10- 8
2.58 X Io- 8
2.70 X io- 8
2.70 X IO-8
Carbon
dioxide .
3 ooXio- 8
3.47X10- 8
3.58X10- 8
3.28X10- 8
3.33X10-8
.As a preliminary to examining further into the nature of molecular motion and the differences of character of this motion, let us try to picture the state of things which would exist in a mass of solid matter in which all the molecules are imagined to be at rest relatively to one another.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ Isomers are molecules with identical molecular formulas but differ in arrangement of their atoms (e.g., glyceraldehyde and dihydroxyacetone).
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

.The fact that a solid body in its natural state is capable both of compression and of dilatation indicates that the molecules of the body must not be supposed to be fixed rigidly in position relative to one another; the further fact that a motion of either compression or of dilatation is opposed by forces which are brought into play in the interior of the solid suggests that the position of rest is one in which the molecules are in stable equilibrium under their mutual forces.^ To spread from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ When measuring with dc current, one would have to take into consideration the electromotive force of the electrochemical cell , and the polarization of the electrodes.

.Such a mass of imaginary matter as we are now considering may be compared to a collection of heavy particles held in position relatively to one another by a system of light spiral springs, one spring being supposed to connect each pair of adjacent particles.^ Silver ions are missing one orbital electron , thus contain 46 orbital electrons, have a positive ionic charge, are not metallic, and therefore are not considered elemental silver.

^ Now they are arranged in order of their atomic number which is the number of   protons (positively charged particles) in the nucleus.

^ An atom may combine chemically with another atom in various ways, either by giving up or receiving electrons, thus setting up an electrical attraction between the atoms (see ion ), or by sharing one or more pairs of electrons.

.Let two such masses of matter be suspended by strings from the same point, and then let one mass be drawn aside, pendulum-wise,.^ Therefore, no matter how far apart are the members of this pair, if the spin is flipped for one of the member, the spin for the other member will also be flipped to the opposite at precisely the same moment.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Water can exist in all three states of matter on Earth, while only in one state on our two nearest neighboring planets.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ Water Water is a major constituent of all living matter consisting of two parts hydrogen and one part oxygen.

and allowed to impinge on the other. After impact the two masses will rebound, and the process may be repeated any number of times, but ultimately the two masses will be found again hanging in contact side by side. .At the first impact each layer of surface molecules which takes the shock of the impact will be thrust back upon the layer behind it: this layer will in this way be set into motion and so influence the layer still further behind;.^ That set way back at the beginning of the Universe.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ Consider an example when the metal ions move preferentially from the metal into the solution: the metal surface becomes negatively charged because of the accumulation of the electrons left behind, while the solution layer near the metal surface becomes positively charged because of the accumulation of silver ions.

^ In chemisorption a single layer of molecules, atoms, or ions is attached to the adsorbent surface by chemical bonds.

and so on indefinitely. .The impact will accordingly result in all the molecules being set into motion, and by the time that the masses have ceased impinging on one another the molecules of which they are composed will be performing oscillations about their positions of equilibrium.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ As a result, it is one of a number of similar molecules being studied for possible uses in organic polymer electronics.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

.The kinetic energy with which the moving mass.^ Reactions almost always go faster at higher temperatures, because the increase in kinetic energy makes the reactants move faster and collide more often.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Application of this rule for p and q to the equation relating the total energy E to the kinetic energy p 2 /2m and the potential energy V(q), e.g., E = p 2 /2m + V(q), yields the time-independent Schrodinger Equation for one particle with mass m and interacting potential V: .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

originally impinged on that at rest is now represented by the energy, kinetic and potential, of the small motions of the individual molecules. .It is known, however, that when two bodies impinge, the kinetic energy which appears to be lost from the mass-motion of the bodies is in reality transformed into heat-energy.^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ Chemical bonds are potential energy, until they are converted into another form of energy, kinetic energy (according to the two laws of thermodynamics).
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ Energy is in two forms: kinetic, or energy in use/motion; and potential, or energy at rest or in storage.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

.Thus the molecular theory of matter, as we have now pictured it, leads us to identify heat-energy in a body with the energy of motion of the molecules of the body relatively to one another.^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ There’s only one Molecule of any importance and it’s the most common in the Universe right from the beginning to today and that is molecular Hydrogen.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ Amino acids are linked together by joining the amino end of one molecule to the carboxyl end of another.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

.A body in which all the molecules were at rest relatively to one another would be a body devoid of heat.^ To spread from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ The spread of cancer from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

This conception of the nature of heat leads at once to an absolute zero of temperature - a temperature of no heat-motion--which is identical, as will be seen later, with that reached in other ways, namely, about - 273° C.
.The point of view which has now been gained enables us to interpret most of the thermal properties of solids in terms of molecular theory.^ Most of the phenomena were described originally from the macroscopic point of view.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.Suppose for instance that two bodies, both devoid of heat, are placed in contact with one another, and that the surface of the one is then rubbed over that of the other.^ To spread from one part of the body to another.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ When two monomers join, a hydroxyl (OH) group is removed from one monomer and a hydrogen (H) is removed from the other.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

.The molecules of the two surface-layers will exert forces upon one another, so that, when the rubbing takes place, each layer will set the molecules of the other into motion, and the energy of rubbing will be used in establishing this heat-motion.^ Also, heat can never be converted 100% into any other form of energy.

^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ When measuring with dc current, one would have to take into consideration the electromotive force of the electrochemical cell , and the polarization of the electrodes.

In this we see the explanation of the phenomenon of the generation of heat by friction. .At first the heat-motion will be confined to molecules near the rubbing surfaces of the two bodies, but, as already explained, these will in time set the interior molecules into motion, so that ultimately the heat-motion will become spread throughout the whole mass.^ Typically, it consists of two metal electrodes immersed into an aqueous solution ( electrolyte ) with electrode reactions occurring at the electrode-solution surfaces.

^ Consider an example when the metal ions move preferentially from the metal into the solution: the metal surface becomes negatively charged because of the accumulation of the electrons left behind, while the solution layer near the metal surface becomes positively charged because of the accumulation of silver ions.

^ These abnormal melanocytes may become cancer and spread into nearby normal tissue.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

Here we have an instance of the conduction of heat.' .When the molecules are oscillating about their equilibrium positions, there is no reason why their mean distance apart should be the same as when they are at rest.^ Therefore, no matter how far apart are the members of this pair, if the spin is flipped for one of the member, the spin for the other member will also be flipped to the opposite at precisely the same moment.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ An electrode or an electrochemical cell is said to be in "equilibrium" when there is no net current flowing and there are no net electrode reactions taking place in the system.

^ Since the virtual photons in between two parallel metal plates placed a short distance apart can exist only when they can form a standing wave , there are fewer photons in each cubic centimeter of vacuum between the plates than there are in the vacuum outside.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

This leads to an interpretation of the fact that a change of dimensions usually attends a change in the temperature of a substance. Suppose for instance that two molecules, when at rest in equilibrium, are at a distance a apart. .It is very possible that the repulsive force they exert when at a distance a - e may be greater than the attractive force they exert when at a distance a + E. If so, it is clear that their mean distance apart, averaged through a sufficiently long interval of their motion, will be greater than a. A body made up of molecules of this kind will expand on heating.^ Molecules made up of H and C are known as hydrocarbons.
  • CHEMISTRY II: WATER AND ORGANIC MOLECULES 24 January 2010 16:37 UTC www.emc.maricopa.edu [Source type: Academic]

^ Methylation of proteins or nucleic acids may affect how they act in the body.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ A type of immune cell that is made in the bone marrow and travels through the blood to tissues in the body where it becomes a macrophage.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.As the temperature of a body increases the average energy of the molecules will increase, and therefore the range of their excursions from their positions of equilibrium will increase also.^ Reactions almost always go faster at higher temperatures, because the increase in kinetic energy makes the reactants move faster and collide more often.
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At a certain temperature a stage will be reached in which it is a frequent occurrence for a molecule to wander so far from its position of equilibrium, that it does not return but falls into a new position of equilibrium and oscillates about this. .When the body is in this state the relative positions of the molecules are not permanently fixed, so that the body is no longer of unalterable shape: it has, assumed a plastic or molten condition.^ It was postulated that the momentum p and position q are no longer mere numbers but are operators satisfying the commutative relation: (qp - pq) = i .
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^ A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.The substance attains to a perfectly liquid state as soon as the energy of motion of the molecules is such that there is a constant rearrangement of position among them.^ While the latter is linked to the oscillating state of the molecule, which occurs only at certain resonant energy so that the emitting or absorbing photon can carry only .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ A substance, such as a detergent, added to a liquid to increase its spreading or wetting properties by reducing its surface tension.

.A molecule escaping from its original position in a body will usually fall into a new position in which it will be held in equilibrium by the forces from a new set of neighbouring molecules.^ In physisorption adsorbed molecules are held by the weaker van der Waals' forces.

^ In presenting the potential curve for a diatomic molecule, one of the atomic nucleus is usually fixed at the origin of the coordinate frame.
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.But if the wandering molecule was originally close to the surface of the body, and if it also happens to start off in the right direction, it may escape from the body altogether and describe a free path in space until it is checked by meeting a second wandering molecule or other obstacle.^ A substance found on certain epithelial cells (cells that cover organs, glands, and other body surfaces) and on breast cells involved in making milk.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Having to do with metastasis, which is the spread of cancer from the primary site (place where it started) to other places in the body.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.The body is continually losing mass by the loss of individual molecules in this way, and this explains the process of evaporation.^ Methyl groups are added or removed from proteins or nucleic acids and may change the way these molecules act in the body.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Dihydroxyacetone phosphate DHAP is an intermediate molecule involved in processes occurring in the body as glycolysis and gluconeogenesis.

^ A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

Moreover, the molecules which escape are, on the whole, those with the greatest energy. .The average energy of the molecules of the liquid is accordingly lowered by evaporation.^ Surface Tension - A molecule in the interior of a liquid is completely surrounded by other molecules, and so, on the average, it is attracted equally in all directions.
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In this we see the explanation of the fall of temperature which accompanies evaporation.
.When a liquid undergoing evaporation is contained in a closed vessel, a molecule which has left the liquid will, after a certain 1 Other processes also help in the conduction of heat, especially in substances which are conductors of electricity.^ The process reversed when heat is removed from the container.
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^ Is an ionic conductor and the electrical conductivity is directly related to the ionic concentration .

^ It is found as early as the 1800s that whenever a substance is dissolved in a liquid the vapor pressure (the pressure at which the rate of evaporation is equal to the .
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number of collisions with other free molecules and with the sides of the vessel, fall back again into the liquid. Thus the process of evaporation is necessarily accompanied by a process of recondensation. .When a stage is reached such that the number of molecules lost to the liquid by evaporation is exactly equal to that regained by condensation, we have a liquid in equilibrium with its own vapour.^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ It is found as early as the 1800s that whenever a substance is dissolved in a liquid the vapor pressure (the pressure at which the rate of evaporation is equal to the .
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^ Surface Tension - A molecule in the interior of a liquid is completely surrounded by other molecules, and so, on the average, it is attracted equally in all directions.
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.If the whole liquid becomes vaporized before this stage is attained, a state will exist in which the vessel is occupied solely by free molecules, describing paths which are disturbed only by encounters with other free molecules or the sides of the vessel.^ It is also being studied in the treatment of side effects from whole-brain radiation therapy for cancer and other conditions.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Silver ions are water-soluble and exist only in the presence of water or other solvent .

^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

.This is the conception which the molecular theory compels us to form of the gaseous state.^ Mathematically, the property of superposition of states is directly related to the special form of linear differential equation , which governs the behaviour of a single particle in quantum theory.
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.At normal temperature and pressure the density of a substance in the gaseous state is of the order of one-thousandth of the density of the same substance in the solid or liquid state.^ Or a liquid substance can be "absorbed" by a solid.

^ It is found as early as the 1800s that whenever a substance is dissolved in a liquid the vapor pressure (the pressure at which the rate of evaporation is equal to the .
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^ Solutes and solvents may be solids, liquids, or gases (see Figure 12-22).
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It follows that the average distance apart of the molecules in the gaseous state is roughly ten times as great as in the solid or liquid state, and hence that in the gaseous state the molecules are at distances apart which are large compared with their linear dimensions. .(If the molecules of air at normal temperature and pressure were arranged in cubical order, the edge of each cube would be about 2.9 X I o - ' cms.; the average diameter of a molecule in air is 2.8X Io - 8 cms.^ Conductance is defined as the reciprocal of the resistance in ohms, measured between the opposing faces of a 1 cm cube of liquid at a specific temperature.

) Further and very important evidence as to the nature of the gaseous state of matter is provided by the experiments of Joule and Kelvin. .These experiments showed that the change in the temperature of a gas, consequent on its being allowed to stream out into a vacuum, is in general very slight.^ The experiment puts ice (at -25 o C) into a container, which is surrounded by a heating coil (generating an uniform heating rate).
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^ However, the interference pattern fades away if the fullerenes are heated by a laser heater (to about 2700 o C) or collide with gas (leaking into the vacuum chamber of the experiment).
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.In terms of the molecular theory this indicates that the total energy of the gas is the sum of the separate energies of its different molecules: the potential energy arising from intermolecular forces between pairs of molecules may be treated as negligible when the matter is in the gaseous state.^ The electrical potential difference between an electrode and a reference electrode.

^ In other words, the equilibrium electrode potential difference between the two electrodes of the cell.

^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

.These two simplifying facts bring the properties of the gaseous state of matter within the range of mathematical treatment.^ Mathematically, the property of superposition of states is directly related to the special form of linear differential equation , which governs the behaviour of a single particle in quantum theory.
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.The kinetic theory of gases attempts to give a mathematical account, in terms of the molecular structure of matter, of all the non-chemical and non-electrical properties of gases.^ The smallest particle of a substance that has all of the physical and chemical properties of that substance.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ This includes all chemical compounds without the chains or rings of carbon atoms, which are termed organic compounds.
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^ The outermost electrons of an atom determine its chemical and electrical properties.

The remainder of this article is devoted to a brief statement of the methods and results of the kinetic theory. .No attempt will be made to follow the historic order of development, but the present theory will be set out in its most logical form and order.^ Historically, the quantum theory began with the attempt to account for the discrepancy between the theoretical and observational blackbody radiation.
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.The Kinetic Theory of Gases. A number of molecules moving in obedience to dynamical laws will pass through a series of configurations which can be theoretically determined as soon as the structure of each molecule and the initial position and velocity of every part of it are known.^ The ions in a solid salt are usually arranged in a definite crystalline structure, each positive ion being associated with a fixed number of negative ions, and vice versa.

^ The former is related to the initial and final states of the molecule, which favors the one step change in the rotational configuration.
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^ However only the positively charged (e.g., silver) cations can pass through the interface.

.The determination of the series of configurations developing out of given initial conditions is not, however, the problem of the kinetic theory: the object of this theory is to explain the general properties of all gases in terms only of their molecular structure.^ An approximate method called Molecular Orbital Theory (MO for short) has been developed for constructing reasonably accurate molecular structure (the wave functions and energy levels) with reasonably computational time.
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^ The more general statement reads: At the quantum level, the most general physical properties of any system must be expressed in terms of complementary pairs of variables, each of which can be better defined only at the expense of a corresponding loss in the degree of definition of the other.
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^ The only problem is molecular Hydrogen is not very good at cooling things down to anything less than a few thousand degrees.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

We are therefore called upon, not to trace the series of configurations of any single gas, starting from definite initial conditions, but to search for features and properties common to all series of configurations, independently of the particular initial conditions from which the gas may have started.
We begin with a general dynamical theorem, whose special application, when the dynamical system is identified with a gas, will appear later. Let qi, q2,.. qr,, be the generalized coordinates of any dynamical system, and let pi, P2,

P. be the corresponding momenta. .If the system is supposed to obey the conservation of energy and to move solely under its own internal forces, the changes in the co-ordinates and momenta can be found from the Hamiltonian equations aE aE qr = 49 - 1 57., gr where q r denotes dg r ldt, &c., and E is the total energy expressed as a function of pi, qi,.^ Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The energy of a system expresses the ability of that system to do some useful work or generate heat.

^ Thermochemistry - It is the application of the first law of thermodynamics (conservation of energy) to processes such as: chemical reactions, phase changes, e.g., boiling and melting, and the formation of solutions.
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.. pn, qn.
When the initial values of p i, q i

pn, qn, are given, the motion can be traced completely from these equations.
Let us suppose that an infinite number of exactly similar systems start simultaneously from all possible values of pi, q1,
. pn, qn, each moving solely under its own internal forces, and therefore in accordance with equations (i). Let us confine our attention to those systems for which the initial values of pi, qi, ... pn, qn lie within a range such that p t is between p i and pi +dpi qi „ „ qi „ qi +dq i , and so on.
Let the product dp i dq i ... dp n dq n be spoken of as the " extension " of this range of values.
.After a time dt the value of p i will have increased to pi+pidt, where p i is given by equations (i), and there will be similar changes in qi, P2, q2, ...^ In some cases, metaplastic changes alone may mean there is an increased chance of cancer developing at the site.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

q,,.
.Thus after a time dt the values of the coordinates and momenta of the small group of systems under consideration will lie within a range such that pi is between pi +pidt and pi +dp,+(pi+ap?dpi) dt „ qi +gidt „ qi+dqi+ (qi +agLdgi) dt, Thus the extension of the range after the interval dt is dp i (i +aidt) dq i (I +?gidt).^ A member of a group of enzymes that can break down proteins, such as collagen, that are normally found in the spaces between cells in tissues (i.e., extracellular matrix proteins).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ For example, the de Broglie wavelength for a 75 ev electron is 2 x 10 -8 cm, thus the spacing between atoms in a crystal is a good diffraction grating for such electron.
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..
or, expanding as far as first powers of dt, dpidqi. .. dpndgni (art+ugi) dt}. From equations (i), we find that aq _ o a pi qi -, so that the extension of the new range is seen to be dp i dq i ... dpndgn, and therefore equal to the initial extension. .Since the values of the co-ordinates and momenta at any instant during the motion may be treated as " initial " values, it is clear that the " extension " of the range must remain constant throughout the whole motion.^ The solvation number is not very exactly defined since its value may depend on the measurement technique.

This result at once disposes of the possibility of all the systems acquiring any common characteristic in the course of their motion through a tendency for their co-ordinates or momenta to concentrate about any particular set, or series of sets, of values. But the result goes further than this. Let us imagine that the systems had the initial values of their co-ordinates and momenta so arranged that the number of systems for which the co-ordinates and momenta were within a given range was proportional simply to the extension of the range. Then the result proves that the values of the coordinates and momenta remain distributed in this way throughout the whole motion of the systems. Thus, if there is any characteristic which is common to all the systems after the motion has been in progress for any interval of time, this same characteristic must equally have been common to all the systems initially. .It must, in fact, be a characteristic of all possible states of the systems.^ Many Worlds - This interpretation states that whenever the world is faced with a choice at the quantum level, the universe divides into many, so that all possible options are followed, i.e., all the states are realized.
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^ The atoms must contain all 47 orbital electrons making the atom complete as a metallic element in its pure state and having no ionic charge.

.It is accordingly clear that there can be no property common to all systems, but it can be shown that when the system contains a gas (or any other aggregation of similar molecules) as part of it there are properties which are common to all possible states, except for a number which form an insignificant fraction of the whole.^ Pamela: This leads us to perhaps go so far as to think perhaps there are other Solar Systems that have the opposite-handedness.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ If the solution contained all ions and no particles, it would be considered an ionic solution, not a colloid since there would be no particles suspended in the water.

^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

These properties are found to account for the physical properties of gases.
Let the whole energy E of the system be supposed equal to Ei+E2, where E2 is of the form E2 = ? (mu 2 +mv 2 +mw 2 + aie12 + x2022 + 2 E(m'u' 2 +%nY 2 +m'w' 2 +0101 2 +0202'+
. +0n'c1)70 2) (2) s' where Oi 3 02, ... en and similarly 01, 03, ... Ow are any momenta or functions of the co-ordinates and momenta or co-ordinates alone which are subject only to the condition that they do not enter into the coefficients a 1, a 2, &c.
.In this expression the first line may be supposed to represent the energy (or part of the energy) of s similar molecules of a kind which we shall call the first kind, the terms 2 (mu 2 +mv 2 +mw 2) being the kinetic energy of translation, and the remaining terms arising from energy of rotation or of internal motion, or from the energy, kinetic and potential, of small vibrations.^ Figure 12-10a Vibrational and Rotational Energy Levels [view large image] .
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^ These large polymers consist of small molecules called amino acids that have both amine and carboxylic acid functional groups.
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^ As a result, it is one of a number of similar molecules being studied for possible uses in organic polymer electronics.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

.The second line in E2 will represent the energy (or part of the energy) of s' similar molecules of the second kind, and so on.^ When writing the formula of a molecule, positive cards (representing positive     atoms) are generally written first; negative cards (representing negative atoms)     are second.

It is not at present necessary to suppose that the molecules are those of substances in the gaseous state. .Considering only those states of the system which have a given value of E2, it can be proved, as a theorem in pure mathematics,' that when s, s', ... are very large, then, for all states except an infinitesimal fraction of the whole number, the values of u, v, w lie within ranges such that (i) the values of u (and similarly of v, w) are distributed among the s molecules of the first kind according to the law of trial and error; and similarly of course for the molecules of other kinds: (ii) E2mu2 E2mv 2 E2mw2 ?2aie12 s S s s s s - s E s' S' s' - - s' ' See Jeans, Dynamical Theory of Gases (1904), ch.^ While the latter is linked to the oscillating state of the molecule, which occurs only at certain resonant energy so that the emitting or absorbing photon can carry only .
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^ If the two atoms are not in the atoms vector they are first added to the molecule WARNING this function adds a single directed bond, only to be used with in Molecule::raisePower().

^ (Note: mono- is not affixed to first element of compound if there is only one atom per molecule, e.g., CO 2 is carbon dioxide, not monocarbon dioxide).
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v.
.A state of the system in which these two properties are true will be called a " normal state "; other states will be spoken of as " abnormal."^ A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The alkenes contain a functional group that is a double bond between two adjacent carbon atoms; one of these bond can be linked to other atoms.
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.Let all possible states of the system be divided into small ranges of equal extension, and of State. these let a number P correspond to normal, and a number p to abnormal, states.^ These abnormal melanocytes may become cancer and spread into nearby normal tissue.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The valence numbers (oxidation numbers or states) for all the elements are listed on the top right of the symbol name in Figure 13-01a .
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^ Many Worlds - This interpretation states that whenever the world is faced with a choice at the quantum level, the universe divides into many, so that all possible options are followed, i.e., all the states are realized.
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What is proved is that, as s, s', ... become very great, the ratio P/p becomes infinite. .Considering only systems starting in the p abnormal ranges, it is clear, from the fact that the extensions of the ranges do not change with the motion, that after a sufficient time most of these systems must have passed into the P normal ranges.^ The more general statement reads: At the quantum level, the most general physical properties of any system must be expressed in terms of complementary pairs of variables, each of which can be better defined only at the expense of a corresponding loss in the degree of definition of the other.
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^ These abnormal melanocytes may become cancer and spread into nearby normal tissue.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ These cells are similar to both monocytes and myelocytes (immature cells that develop into different types of immune system cells).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.Speaking loosely, we may say that there is a probability P/(P+p), amounting to certainty in the limit, that one of these systems, selected at random, will be in the normal state after a sufficient time has elapsed.^ Since the quantum state is specified by momentum, energy, angular momentum, or spin and there is an uncertainty in determining their value, it implies that a particle can occupy many quantum states (with different probability).
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^ Decoherence - It is suggested that coupling between a quantum system in a superposition and the environment in which it is embedded leads the system to 'collapse' or decay over time into one state or another.
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^ Solution - A solution is a mixture in which one substance called the solute (the component that changes state upon dissolving or in smaller amount) is uniformly dispersed in another substance called the solvent.
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.Again, considering the systems which start from the P normal ranges, we see that there is a probability p/(P+p) which vanishes in the limit, that a system selected at random from these will be in an abnormal state after a sufficient time.^ Pamela: So what sorts of things do you see as these Stars slowly start to light up?
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ These abnormal melanocytes may become cancer and spread into nearby normal tissue.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Since the quantum state is specified by momentum, energy, angular momentum, or spin and there is an uncertainty in determining their value, it implies that a particle can occupy many quantum states (with different probability).
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.Thus, subject to a probability of error which is infinitesimal in the limit, we may state as general laws that A system starting from an abnormal state tends to assume the normal state; while A system starting from the normal state will remain in the normal state. It will now be found that the various properties of gases follow from the supposition that the gas is in the normal state.^ Thus, the boundary between the two extremes, where a quantum system have enough contact with the outside world to start behaving like a classical object, is currently a subject of active research.
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^ The more general statement reads: At the quantum level, the most general physical properties of any system must be expressed in terms of complementary pairs of variables, each of which can be better defined only at the expense of a corresponding loss in the degree of definition of the other.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Transition elements generally exhibit high density, high melting point, magnetic properties, variable valence, and the formation of stable coordination complexes.

.If each of the fractions (3) is put equal to i/4h, it is readily found, from the first property of the normal state, that, of the s molecules of the first kind, a number sal (h3m3 /13)e hm (u2+v2+w2)dudvdw (4) Velocities. have velocities of which the components lie between u and u+du, v and v+dv, w and w+dw, while the corresponding number of molecules of the second kind is, similarly, s' y (h3m'3/73)e hm'(u2-1-v2+"' 2)dudvdw. (5) If c is the resultant velocity of a molecule, so that c 2 =u2+v2+w2, it is readily found from formula (4) that the number of molecules of the first kind of which the resultant velocity lies between c and c+dc is 4lrs1,l (h 3 rn 3 17r 3)e hmc2 c 2 dc. (6) These formulae express the " law of distribution of velocities " in the normal state: the law is often called Maxwell's Law of Distribution. If 2mu 2 denote the mean value of 2mu 2 averaged over the s molecules of the first kind, equations (3) may be written in the form Z mu g = 2 mv 2 = 2 mw 2 = 2x,0 2 1 =.^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

^ As a result, it is one of a number of similar molecules being studied for possible uses in organic polymer electronics.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

^ The calibration is usually carried out with high purity potassium chloride solutions, and the resulting calibration constant is often called the "cell constant."

.. = I /4 h, (7) showing that the mean energy represented by each term in E2 (fotinula 2) is the same. .These equations express the " law of equipartition of energy," commonly spoken of as the Maxwell-Boltzmann Law. The law of equipartition shows that the various mean energies of different kinds are all equal, each being measured by the quantity 1/4h.^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ All quantum particles can be thought of as being surrounded by a cloud of virtual particles (and pairs) of various kinds, which are being created and (usually) reabsorbed by the parent particle.
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^ The first difference is that whereas classical theory always deals with continuously varying quantities, quantum theory must also deal with discontinuous or indivisible processes (e.g., the unit of energy packed in a quantum).
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.We have already seen that the#mean energy increases with the temperature: it will now be supposed that the mean energy is exactly proportional to the ture. temperature.^ Reactions almost always go faster at higher temperatures, because the increase in kinetic energy makes the reactants move faster and collide more often.
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^ Particle surface area is inversely proportional to particle size, which means for a constant concentration of particles, the surface area increases as the particle size decreases.

The complete justification for this supposition will appear later: a partial justification is obtained as soon as it is seen how many physical laws can be explained by it. .We accordingly put 1/2h = RT, where T denotes the temperature on the absolute scale, and then have equations (7) in the form mu 2 = mv '2 = ...^ The boson gas can form Bose-Einstein condensate near absolution zero temperature.
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=RT. .(8) When a system is composed of a mixture of different kinds of molecules, the fact that h is the same for each constituent [cf.^ If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

formulae .(5) and (6)] shows that in the normal state the different substances are all at the same temperature.^ These pictures can show the difference between normal and diseased tissue.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ An ORME has the same number of neutrons , protons , and electrons as the normal element but the physical properties are dramatically different because the electrons have been rearranged and become stable at an increased energy state.

.For instance, if the system is composed of a gas and a solid boundary, some of the terms in expression (2) may be supposed to represent the kinetic energy of the molecules of the boundary, so that equations (7) show that in the normal state the gas has the same temperature as the boundary.^ An ORME has the same number of neutrons , protons , and electrons as the normal element but the physical properties are dramatically different because the electrons have been rearranged and become stable at an increased energy state.

^ Application of this rule for p and q to the equation relating the total energy E to the kinetic energy p 2 /2m and the potential energy V(q), e.g., E = p 2 /2m + V(q), yields the time-independent Schrodinger Equation for one particle with mass m and interacting potential V: .
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^ Here we'll show you some real molecules that have unusual, ridiculous or downright silly names.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

.The process of equalization of temperature is now seen to be a special form of the process of motion towards the normal state: the general laws which have been stated above in connexion with the normal state are seen to include as special cases the following laws: Matter originally at non-uniform temperature tends to assume a uniform temperature; while Matter at uniform temperature will remain at uniform temperature. It will at once be apparent that the kinetic theory of matter enables us to place the second law of thermodynamics upon a purely dynamical basis.^ Before the development of high energy physics, it has been found convenient to divide natural phenomena into two broad classes: one consists of changes of an apparently permanent nature involving the transformation of one form of matter into another, while in the second are included temporary changes, general resulting from an alteration of external conditions.
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^ Mathematically, the property of superposition of states is directly related to the special form of linear differential equation , which governs the behaviour of a single particle in quantum theory.
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^ It is the arsenic equivalent of pyrrole, and although it is rarely found in its pure form, it is occasionally seen as a sidegroup in the form of organic arsolyls .
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So far it has not been necessary to suppose the matter to be in the gaseous state. We now pass to the consideration of laws and properties which are peculiar to the gaseous state.
.A simple approximate calculation of the pressure exerted by a gas on its containing vessel can be made by supposing that the molecules are so small in comparison with their distances apart that they may be treated as of infinitesimal size.^ A condition in which the blood contains high levels of large proteins and is too thick to flow through small blood vessels.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ These chains are made up of small repeating units of molecules called monomers.
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^ A small molecule made of one carbon and three hydrogen atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.Let a mixture of gases contain per unit volume v molecules of the first kind, v' of the second kind, and so on.^ Pamela: So we get Stars forming, what are the first Molecules we want beyond H 2 to start cropping up with the mixture?
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ (Note: mono- is not affixed to first element of compound if there is only one atom per molecule, e.g., CO 2 is carbon dioxide, not monocarbon dioxide).
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^ This provides an atomistically fundamental unit because one gram-mol of any material will contain the same (and very large) number of molecules .

Let us fix our attention on a small area dS of the boundary of the s (3) qi „ and so on.
+.. . '}'anent) vessel, and let co-ordinate axes be taken such that the origin is in dS, and the axis of x is the normal at the origin into the gas. .The number of molecules of the first kind of gas, whose components of velocity lie within the ranges between u and u+du, v and v+dv, w and w+dw, will, by formula (5), be v?l (h 3 m 3 /7 3)e hm (u2+v2+w2)dudvdw (9) per unit volume.^ (Note: mono- is not affixed to first element of compound if there is only one atom per molecule, e.g., CO 2 is carbon dioxide, not monocarbon dioxide).
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^ You see what you have within the first Proto-Galaxies are large clouds of hot gas.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ This provides an atomistically fundamental unit because one gram-mol of any material will contain the same (and very large) number of molecules .

.Construct a small cylinder inside the gas, having dS as base and edges such that the projections of each on the coordinate axes are udt, vdt, wdt. Each of the molecules enumerated in expression (9) will move parallel to the edge of this cylinder, and each will describe a length equal to its edge in time dt. Thus each of these molecules which is initially inside the cylinder, will impinge on the area dS within an interval dt. The cylinder is of volume u dt dS, so that the product of this and expression (9) must give the number of impacts between the area dS and molecules of the kind under consideration within the interval dt. Each impinging molecule exerts an impulsive pressure equal to mu on the boundary before the component of velocity of its centre of gravity normal to the boundary is reduced to zero.^ Argyria is known to be caused by ingesting; 1) silver salts (compounds) such as silver nitrate, 2) high concentrations of ionic silver, 3) protein based silver products aka "silver protein" or "mild silver protein" .

^ These large polymers consist of small molecules called amino acids that have both amine and carboxylic acid functional groups.
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^ In a a liquid environment such as the inside of cells, these properties dictate how a protein "assembles", or folds (Figure 12-16d).
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.Thus the contribution to the total impulsive pressure exerted on the area dS in time dt from this cause is mu X udtdS X (11 3 m 3 /,r 3)e hm (u2+v2+w2 )dudvdw (I o) The total pressure exerted in bringing the centres of gravity of all the colliding molecules to rest normally to the boundary is obtained by first integrating this expression with respect to u, v, w, the limits being all values for which collisions are possible (namely from - co too for u, and from - oo to + oo for v and w), and then summing for all kinds of molecules in the gas.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ All quantum particles can be thought of as being surrounded by a cloud of virtual particles (and pairs) of various kinds, which are being created and (usually) reabsorbed by the parent particle.
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^ It gets its name from the Swedish plant Garden Angelica ( Archangelica officinalis ) from whose roots it was first obtained in the 1840s.
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.Further impulsive pressures are required to restart into motion all the molecules which have undergone collision.^ To dissociate a NaCl molecule into Na and Cl atoms requires an energy of 4.2 ev, breaking it up into Na + and Cl - ions requires an additional energy of 1.3 ev.
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.The aggregate amount of these pressures is clearly the sum of the momenta, normal to the boundary, of all molecules which have left dS within a time dt, and this will be given by expression (pp), integrated with respect to u from o to and with respect to v and w from - oo to +oo, and then summed for all kinds of molecules in the gas.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Pamela: So we have all of these Molecules popping up.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

.On combining the two parts of the pressure which have been calculated, the aggregate impulsive pressure on dS in time dt is found to be dS ff f v1,1 (h 3 m 3 /7r 3)e h m(u2+v2+w2 >mu2dudvdw, where M denotes summation over all kinds of molecules.^ However, if the spin of the two electrons is antiparallel as shown in the left side of Figure 12-08, the two atoms combine to form a hydrogen molecule.
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^ It is found that water molecules spend more time around certain areas of DNA when cell divides.
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^ Water Water is a major constituent of all living matter consisting of two parts hydrogen and one part oxygen.

.This is equivalent to a steady pressure p i per unit area where +0 pi - zfff v J 1 (h3m3/ir3)e hm(u2+v2+w2)mu2dudvdw. Clearly the integral is the sum of the values of mu g for all the molecules of the first kind in unit volume, thus p=v mu l +v'm'u 2 +...^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Lintott: Oh well, pretty good laboratory vacuums, all right, [Laughter] a few thousand Molecules per cubic centimeter at the most, at the absolute most.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ (Note: mono- is not affixed to first element of compound if there is only one atom per molecule, e.g., CO 2 is carbon dioxide, not monocarbon dioxide).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

(I
I) On substituting from equations (7) and (8), this expression assumes the forms p =(v+7/±...) /2h _ (v -F v' -{-. ..) .RT The number of molecules per unit volume in a gas at normal temperature and pressure is known to be about 2.75 X 10 19. If in formula Molecular (?3) we put p=I 013X10 6, (v +v'+ ..^ Strictly speaking, one must use unit activity rather than concentration of hydrogen ions and unit fugacity rather than unit pressure of hydrogen gas.

^ So once you form the molecular Hydrogen, you can cause a cloud of gas to cool to a critical temperature where it can collapse to form a Star.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ This provides an atomistically fundamental unit because one gram-mol of any material will contain the same (and very large) number of molecules .

.)=2.75X1019 r .Velocities.
T =273, we obtain R =1.35 X Io -16 and this enables us to determine the mean velocities produced by heat motion in molecules of any given mass. For molecules of known gases the calculation is still easier.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.If p is the density corresponding to pressure p, we find that,}, formula (Ii) assumes the form P = 3PC2, where C is a velocity such that the gas would have its actual translational energy if each molecule moved with the same velocity C. By substituting experimentally determined pairs of values of p and p we can calculate C for different gases, and so obtain a knowledge of the magnitudes of the molecular velocities.^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ Hydrogen bonds are important in fixing properties such as solubilities, melting points, and boiling points, and in determining the form and stability of crystalline structures.
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^ It has the same chemical formula as glucose (the chief source of energy for living organisms) but has a different arrangement of atoms.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

For instance, it is found that for hydrogen at o° Cent. C =183,900 cms. per sec.
„ air 15° C = 49,800 „ „ „ mercury vapour at o° „ C = 18,500 „ and other velocities can readily be calculated.
.From the value R = I. 35 X I 016 it is readily calculated that a molecule, or aggregation of molecules, of mass Io - 12 grammes, ought to have a mean velocity of about 2 millimetres a second at O.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

.C. Such a velocity ought accordingly to be set up in a part i cle of -12 grammes mass immersed in air or liquid at 0° C., by the continual jostling of the surrounding molecules or particles.^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ A notional boundary at the diffuse (second layer) of ions surrounding a particle dispersed in a liquid is known as the hydrodynamic boundary layer.

^ The liquid layer surrounding the particle exists as two parts; an inner region (Stern layer) where the ions are strongly bound and an outer (diffuse) region where they are less firmly associated.

A particle of this mass is easily visible microscopically, and a velocity of 2 mm. per second would of course be visible if continued for a sufficient length of time. Each bombardment will, however, change the motion of the particle, so that changes are too frequent for the separate motions to be individually visible. .But it can be shown that from the aggregation of these separate short motions the particle ought to have a resultant motion, described with an average velocity which, although much smaller than 2 mm.^ Very small particles whose size is greater than an atom but smaller than conventional small particles.

^ These forces are much weaker than those arising from valence bonds are inversely proportional to the seventh power of the distance between the atoms or molecules .

a second, ought still to be microscopically visible. It has been shown by R. von. S. Smoluchowski (Ann. d. Phys., 1906, 21, p. 756) that this theoretically predicted motion is simply that seen in the " Brownian movements " first observed by the botanist Robert Brown in 1827. Thus the " Brownian movements " provide visual demonstration of the reality of the heat-motion postulated by the kinetic theory. Dalton's Law. - .The pressure as given by formula (12) can be written as the sum of a number of separate terms, one for each gas in the mixture.^ Strictly speaking, one must use unit activity rather than concentration of hydrogen ions and unit fugacity rather than unit pressure of hydrogen gas.

^ A molecular formula is a symbolic representation of the composition of a compound in terms of its constituent elements (e.g., H 2 O, CH 4 , C 6 H 12 O 6 , ...
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Hence we have Dalton's law: constituents if each alone were present. sures which would be exerted separately by the several The pressure of a mixture of gases is the sum of the pres- Avogadro's Law. - From formula (13) it appears that v+v'+.. ., the total number of molecules per unit volume, is determined when p, T and the constant R are given. .Hence we have Avogadro's law: Different gases, at the same temperature and pressure, contain equal numbers of molecules per unit volume.^ This provides an atomistically fundamental expression because one gram-mol of any material will contain the same (and very large) number of molecules .

^ This provides an atomistically fundamental unit because one gram-mol of any material will contain the same (and very large) number of molecules .

^ One gram-mol of hydrogen gas contains the exact same number of molecules as one gram-mol of table salt (sodium chloride), even though the latter is much heavier.

Boyle's and Charles Laws. - If v
is the volume of a homogeneous mass of gas, and N the total number of its molecules, N =v(v+v'+ ...), so that .pv =RNT. (14) In this equation we have the combined laws of Boyle and Charles: When the temperature of a gas is kept constant the pressure varies inversely as the volume, and when the volume is kept constant the pressure varies as the temperature. Since the volume at constant pressure is exactly proportional to the absolute temperature, it follows that the coefficients of expansion of all gases ought, to within the limits of error introduced by the assumptions on which we are working, to have the same value 1/273. Van der Waals's Equation.^ The force accounts for the term a/V 2 in van der Waals’ equation.

^ The van der Waals interaction is about 10 times weaker than hydrogen bond.
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^ Figure 12-17 van der Waals Interaction [view large image] .
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- The
laws which have just been stated are obeyed very approximately, but not with perfect accuracy, by all gases of which the density is not too great or the temperature too low. .Van der Waals, in a famous monograph, On the Continuity of the Liquid and Gaseous States (Leiden, 1873), has shown that the imperfections of equation (14) maybe traced to two_causes: (i.^ The force accounts for the term a/V 2 in van der Waals’ equation.

^ Individual atoms in close proximity to other like atoms will be pulled together by van der Waals' force and form particles.

^ In physisorption adsorbed molecules are held by the weaker van der Waals' forces.

) .The calculation has not allowed for the finite size of the molecules, and their consequent interference with one another's motion, and (ii.^ The opposite charges within molecules create the   force or the chemical "glue" that bonds or holds atoms to one another.

^ Molecules are made up of atoms that are bonded to one-another.

^ When the two wings are directly over one another, they look like a WW1 biplane, and so this group of molecules has been termed 'biplanenes'.
  • Molecules with Silly or Unusual Names 24 January 2010 16:37 UTC www.chm.bris.ac.uk [Source type: FILTERED WITH BAYES]

) .The calculation has not allowed for the field of inter-molecular force between the molecules, which, although small, is known to have a real existence.^ Usually this relies on the force of gravity, but if the particles are too small or the difference between the solid and liquid phase is too small, a centrifuge may be used.

^ A difference in the direction of the bond between the glucose molecules allows us to digest the starches in our cereals and bread, but not the cellulose in their packaging.
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^ Waals’ force – An attractive force between atoms and molecules, named after J. D. van der Waals (1837-1923).

.The presence of this field of force results in the molecules, when they reach the boundary, being acted on by forces in addition to those originating in their impact with the boundary.^ As a result, it is one of a number of similar molecules being studied for possible uses in organic polymer electronics.
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^ These forces are much weaker than those arising from valence bonds are inversely proportional to the seventh power of the distance between the atoms or molecules .

.To allow for the first of these two factors, Van der Waals finds that v in equation '04) must be replaced by v - b, where b is four times the aggregate space occupied by all the molecules, while to allow for the second factor, p must be replaced by p +a/v 2 . Thus the pressure is given by the equation (p+a/v 2) (v - b) =RNT, which is known as Van der Waals's equation.^ The force accounts for the term a/V 2 in van der Waals’ equation.

^ The atoms in a silver particle remain held together by van der Waals’ force of attraction that causes like (identical) atoms to be attracted to each other.

^ In physisorption adsorbed molecules are held by the weaker van der Waals' forces.

This equation is found experimentally to be capable of representing the relation between p, v, and T over large ranges of values. (See Condensation Of Gases.) .Let us consider a single gas, consisting of N similar molecules in a volume v, and let the energy of each molecule, as in formula (2) be given by E = 2P i (mu 2 +mv 2 +mw 2 +a101 2 +.^ Consisting of molecules that have only single bonds (i.e.

.. anen t) .(15) =N(n+3)/4h by equation (7) 2 (n+3)RNT. (16) Let a quantity dQ of energy, measured in work units, be absorbed by the gas from some external source, so that its pressure, volume and temperature change.^ Symbol eV. A unit of energy equal to the work done on an electron in moving it through a potential difference of one volt.

^ It expresses the ability of an electrical source to carry out useful work or generate heat; for example, this energy can be used to drive an electrical motor and carry out some mechanical work, or to generate heat with an electrical heater.

^ Strictly speaking, one must use unit activity rather than concentration of hydrogen ions and unit fugacity rather than unit pressure of hydrogen gas.

.The equation of energy is dQ=dE+pdv, (17) expressing that the total energy dQ is used partly in increasing the internal energy of the gas, and partly in expanding the gas against the pressure p. If we take p = RNT/v from equation (14) and substitute for E from equation (16), this last equation becomes dQ 2 (n +3)RNdT +RNTdv (18) which may be taken as the general equation of calorimetry, for a gas which accurately obeys equation (14).^ Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ This creates high-energy radiation that may be used to treat cancer.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Strictly speaking, one must use unit activity rather than concentration of hydrogen ions and unit fugacity rather than unit pressure of hydrogen gas.

Second Law of Thermodynamics

If we divide throughout by T, we obtain d 2 (n+3)RN T +RNd v, showing that dQ/T is a perfect differential. This not only verifies that the second law of thermodynamics is obeyed, but enables us to identify T with the absolute thermodynamical temperature. If the volume of the gas is kept constant, we put dv=o in equation (18) and dQ = JC0NmdT, where C v is the specific Specific heat of the gas at constant volume and J is the mechanical equivalent of heat. We obtain Cv = z (n +3) R /J m. (19) On the other hand, if the pressure of the gas is ke p t constant throughout the motion, T/v is constant and dQ = JC,,NmdT, whence C 5 = z (n +5) R /Jm. (20) By division of the values of C, and C„ we find for -y, the ratio of the specific heats.
y =1 + 2/(n+3). (21) The comparison of this formula with experiment provides a striking confirmation of the truth of the kinetic theory but at the same time discloses the most formidable difficulty which the theory has so far had to encounter.
.On giving different values to n in formula (21), we obtain the values for y: n = o, 1, 2, 3, 4, 5, y = 1.66, 1.5, 1.4, 1.33, 1.28, 1.25, &c.^ Because a measurement gives the conductance, methods have been devised to convert the measured value to the conductivity, so that results can be compared from different experiments.

.Thus, to within the degree of approximation to which our theory is accurate, the value of y for every gas ought to be one of this series.^ Carbon acid gas Carbon dioxide, CO2, is one of the gases in our atmosphere, which is uniformly distributed over the earth's surface.

The following are the values of y for gases for which y can be observed with some accuracy: Mercury.. 1.66 Nitrogen.. 1.40 Krypton.. 1 66 Carbon monoxide.. 1.41 Helium.. 1.65 Hydrogen. ... 1.40 Argon. 1.62 Oxygen. .. I.40 Air.. 1.40 Hydrochloric acid.. 1.39 It is clear that for the first four gases n = o, while for the remainder n=2. To examine what is meant by a zero value of n we refer to formula (15). .The value of n is the number of terms in the energy of the molecule beyond that due to translation.^ Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence ).

Thus when n = o, the whole energy must be translational: there can be no energy of rotation or of internal motion. .The molecules of gases for which n = o must accordingly be spherical in shape and in internal structure, or at least must behave at collisions as though they were spherical, for they would otherwise be set into rotation by the forces experienced at collisions.^ When measuring with dc current, one would have to take into consideration the electromotive force of the electrochemical cell , and the polarization of the electrodes.

^ That promotes the Electrons in the Molecule up into higher energy levels and then they drop back down and emit the radio waves.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

.In the light of these results it is of extreme significance that the four gases for which n = o are all believed to be monatomic: the molecules of these gases consist of single atoms.^ Consisting of molecules that have only single bonds (i.e.

^ The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ These large polymers consist of small molecules called amino acids that have both amine and carboxylic acid functional groups.
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Moreover, these four are the only monatomic gases for which the value of y is known, so that the only atoms of which the shape can be determined are found to be spherical. .It is at least a plausible conjecture, until the contrary is proved, that the atoms of all elements are spherical.'^ The number of protons in the nucleus of a nuclide; all the atoms of a chemical element have the same atomic number; sometimes indicated by a subscript preceding the symbol of a chemical element (e.g., 1 H).

^ The atoms must contain all 47 orbital electrons making the atom complete as a metallic element in its pure state and having no ionic charge.

^ In an element, all the atoms have the same number of protons and electrons , although the number of neutrons may vary.

.The next value which occurs is n =2. The kinetic energy of the molecules of these gases must contain two terms in addition to those representing translational energy.^ While the latter is linked to the oscillating state of the molecule, which occurs only at certain resonant energy so that the emitting or absorbing photon can carry only .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Lintott: Oh well to get to what happens to get these to emit the radio waves that we’re seeing, you just bash two Molecules together.
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

^ Pamela: So, once you find the Carbon-Monoxide, what other sorts of Molecules do you find next as you peer through these Star-forming regions?
  • Astronomy Cast - Ep. 116: Molecules in Space 24 January 2010 16:37 UTC www.astronomycast.com [Source type: General]

For a rigid body the kinetic energy will, in general, consist of three terms (AW1 2 +BW2 2 +CW3 2) in addition to the translational energy. .The value n = 2 is appropriate to bodies of which the shape is that of a solid of revolution, so that there is no rotation about the axis of symmetry.^ Abelian group (e.g., the two dimensional rotation about the z-axis).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

We must accordingly suppose that the molecules of gases for which n =2 are of this shape. .Now this is exactly the shape which we should expect to find in molecules composed of two spherical atoms distorting one another by their mutual forces, and all gases for which n=2 are diatomic.^ Molecules are made up of atoms that are bonded to one-another.

^ For example, the formula H 2 O   shows that the molecule is composed of two H atoms and one O atom.

^ A symbol is   composed of one or two letters that have been assigned to represent that particular   element.

No molecule could possibly be imagined for which n had a negative value or the value n =1. The theory therefore passes a crucial test when it is discovered that no gases exist for which n is either negative or unity. .On the other hand, the theory encounters a very serious difficulty in the fact that all molecules possess a great number of possibilities of internal motion, as is shown by the number of distinct lines in their spectra both of emission and of absorption.^ ORMEs will produce different atomic absorption/emission spectral lines than normal elements which make their presence difficult to detect using atomic absorption/emission based spectroscopy.

^ This provides an atomistically fundamental expression because one gram-mol of any material will contain the same (and very large) number of molecules .

^ This provides an atomistically fundamental unit because one gram-mol of any material will contain the same (and very large) number of molecules .

.So far as is known, each line in the spectrum of, say, mercury, represents a possibility of a distinct vibration of the mercury atom, and accordingly provides two terms (say aq;, 2 +.^ The solid line denotes a bond with two sharing electrons in between the atoms, while the dot represents the electron not in a bond.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

42, where (1 5, is the normal co-ordinate of the vibration) in the expression for the energy of the molecule. There are many thousands of lines in the mercury spectrum, so that from this evidence it would appear that for mercury vapour n ought to be very great, and y almost equal to unity. .Instead of this we have n = o, and -y = I I. As a step towards removing this difficulty we notice that the energy of a vibration such as is represented by a spectral line has the peculiarity of being unable to exist (so far as we know) without suffering dissipation into the ether.^ It is being studied in the treatment of cancer symptoms such as lack of energy, pain, swelling, and depression.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ Each of the vibrational energy level v is further split into a series of rotational energy levels J called vibrational band.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.This energy, therefore, comes under a different category from the energy for which the law of equipartition was proved, for in proving this law conservation of ' Very significant confirmation of this conjecture is obtained from a study of the specific heats of the elements in the solid state.^ It is a fundamental law of nature that energy can never be converted from one form to another 100%, some of the energy is always converted into heat energy during the conversion.

^ ORMEs are atoms of elements whose orbital electrons have been altered from the energy state as it normally exists in the element.

^ Since the quantum state is specified by momentum, energy, angular momentum, or spin and there is an uncertainty in determining their value, it implies that a particle can occupy many quantum states (with different probability).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

If a solid body is regarded as an aggregation of similar atoms each of mass m, its specific heat C is given, as in formula (19) by C = i (n+3) R/Jm. .From Dulong and Petit's law that Cm is the same for all elements, it follows that n+3 must be the same for all atoms.^ All elements in a period have the same number of shells of electrons.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ In an element, all the atoms have the same number of protons and electrons , although the number of neutrons may vary.

^ Elements within the same group all have the same number of electrons in their outer shell.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

Moreover, the value of Cm shows that n+3 must be equal to six. .Now if the atoms are regarded as points or spherical bodies oscillating about positions of equilibrium, the value of n+3 is precisely six, for we can express the energy of the atom in the form (9 2 v a 2 v a2v E = z(mu 2 +mv 2 +mw 2 +x 2 ax2 + y2ay2-fz2az2), where V is the potential and x, y, z are the displacements of the atom referred to a certain set of orthogonal axes.^ In traditional Chinese medicine, one of 20 channels that form a network through which qi (the body's vital energy) flows and that connect the body’s acupuncture sites.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

^ The valence of a free atom is zero, but in a chemical compound, the value has some positive or negative value.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ We cannot measure the "absolute" potential of an electrode; therefore, the electrode potential must always be referred to an "arbitrary zero point," defined by the potential of the reference electrode .

energy was assumed. .The difficulty is further diminished when it is proved, as it can be proved, 2 that the modes of energy represented in the atomic spectrum acquire energy so slowly that the atom might undergo collisions with other atoms for centuries before being set into oscillations which would possess an appreciable amount of energy.^ To dissociate a NaCl molecule into Na and Cl atoms requires an energy of 4.2 ev, breaking it up into Na + and Cl - ions requires an additional energy of 1.3 ev.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Covalent Bonds - Since a carbon atom has four valence electrons, which can be shared with other atoms to achieve an octet (a stable closed atomic shell).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ The amount of energy required to break a bond and produce neutral atoms is called the bond energy.

.In fact the proved tendency for the gas to pass into the " normal state " in which there is equipartition of energy, represents in this case nothing but the tendency for the translational energy to become dissipated into the energy of innumerable small vibrations.^ Each of the vibrational energy level v is further split into a series of rotational energy levels J called vibrational band.
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ ORMEs are atoms of elements whose orbital electrons have been altered from the energy state as it normally exists in the element.

^ Since the quantum state is specified by momentum, energy, angular momentum, or spin and there is an uncertainty in determining their value, it implies that a particle can occupy many quantum states (with different probability).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

.We find that this dissipation, although undoubtedly going on, proceeds with extreme slowness, so that the vibrations pass their energy on to the ether as rapidly as they acquire it, and the " normal state " is never established.^ They will pass from the phase where the "chemical energy" of the ion is large to the phase where the "chemical energy" of the ion is smaller.

^ ORMEs are atoms of elements whose orbital electrons have been altered from the energy state as it normally exists in the element.

These considerations suggest that the difficulty which has been pointed out may be apparent rather than real. .At the same time this difficulty is only one aspect of a wider difficulty which cannot be lightly passed over; Maxwell himself regarded it as the principal obstacle in the way of the full acceptance of the theory of which he was so largely the author.^ The Pauli Exclusion Principle states that identical fermions -- one type of fundamental matter with 1/2 integer spin quantum number -- cannot be in the same place at the same time and with the same orientation (i.e., cannot have the same quantum state).
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ Since it implies that p cannot be a function of q (because it would mean p and q can be determined precisely at the same time), p can be related to q only in the form of an operator such as - i d/dq, where i = .
  • Molecules 24 January 2010 16:37 UTC universe-review.ca [Source type: FILTERED WITH BAYES]

^ In a clinical trial, median survival time is one way to measure how effective a treatment is.
  • Dictionary of Cancer Terms - National Cancer Institute 24 January 2010 16:37 UTC www.cancer.gov [Source type: Academic]

(J. H. JE.)

<< Mole

Simple English

[[File:|200px|thumb|right|This is a sugar molecule. Carbon atoms are made blue, oxygen atoms are made red and hydrogen atoms are made white to show the difference. In reality atoms do not have a color.]] A molecule is the smallest amount of a chemical substance that can exist. If a molecule were split into smaller pieces, it would be a different substance.

Molecules are made up of atoms that are stuck together in a particular shape or form. Not all combinations of atoms are usually possible; atoms like certain shapes, but not others. For example, oxygen atoms always have two bonds with other atoms, carbon atoms always have four bonds with other atoms, and nitrogen atoms always have three bonds with other atoms.

In gases like air, the molecules are just flying around. In liquids like water, the molecules are stuck together but they can still move. In solids like sugar, the molecules can only vibrate.

With a molecular formula, you can write down the numbers of all atoms in a molecule. For example, the molecular formula of sugar is C6H12O6. That means that one molecule of sugar is made up of six carbon atoms, twelve hydrogen atoms and six oxygen atoms.

Bonding

For a molecule to exist, atoms have to stick together. This happens when two atoms share electrons. Instead of circling just one atom, the electron now circles around two. This is called bonding. The shared electrons are called 'bonds'. Sometimes, more than one electron is shared. The more electrons are shared, the stronger the bond gets and the stronger the atoms stick together.

Bonds can also be broken apart. Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels. For example, a candle will just sit there and nothing happens. But when you use a match to light it, it will burn for a long time. The match brings the energy to break the first bonds, which release enough energy to break the bonds below them, until the candle has burned down.

Particles in Physics
Elementary: Fermions: Quarks: up - down - strange - charm - bottom - top
Leptons: electron - muon - tau - neutrinos
Bosons: Gauge bosons: photon - W and Z bosons - gluons
Composite: Hadrons: Baryons: proton - neutron - hyperon
Mesons: pion - kaon - J/ψ
Atomic nuclei - Atoms - Molecules
Hypothetical: Higgs boson - Graviton - Tachyon

Other websites


Citable sentences

Up to date as of December 25, 2010

Here are sentences from other pages on Molecule, which are similar to those in the above article.








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