atomictheory

atomictheory - measurements of the charge in a single...

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atomic theory of matter  - developed by John Dalton   all elements are composed of atoms atoms in each element are identical chemical reactions can't change, create, or destroy atoms compounds are combinations of atoms atoms - smallest particles of an element that still contain all the characteristics of that element law of constant composition - kinds of atoms and their ratios are constant in compounds law of conservation of mass - total mass after a reaction is equal to total mass before the reaction law of multiple proportions - atoms combine in compounds in simple ratios cathode ray tubes  - vacuum tube through which high voltage creates radiation   produce rays that cause glass to fluoresce, give off light electrons move from the cathode (-) to the anode (+) J. J. Thomson - summarized his cathode ray observations and found the electron's electrical charge to be 1.76 x 108 coulombs per gram Robert Millikan - used his "oil-drop" experiment to calculate the mass of the electron by using his
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Unformatted text preview: measurements of the charge in a single electron and Thomson's calculations radioactivity - spontaneous emission of radiation • Ernest Rutherford - aka "the second Newton"; discovered the 3 types of radiation • alpha radiation- positive charge, more massive than beta; equal to nuclei of helium • beta radiation- negative charge, less massive than alpha; equal to high speed electrons/cathode rays • gamma radiation- unaffected by electrical fields, has no charge nuclear atom - final view of atom discovered by Rutherford • J. J. Thomson - believed that electrons were embedded in a positively charged sphere • Ernest Rutherford - used gold foil experiment to prove that positive charge resided in a very small, dense region called the nucleus • protons discovered by Rutherford in 1919 • neutrons discovered by James Chadwick in 1932...
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This document was uploaded on 10/30/2011 for the course CHEM 161 at Rutgers.

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