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Period: to
Atomic Models Timeline
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John Dalton
Brought back atomic theory and atoms based upon measurable properties of mass. -
John Dalton
He had the idea that the atom was just a sphere. -
Dmitri Mendeleev
He created 7 groups which he put the elements in them. He discovered that the properties of elements "were periodic functions of the their atomic weights". He discovered the Periodic Law. -
Dmitri Mendeleev Model
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Eugene Goldstein
Used a CRT to study "canal rays" which had electrical and magnetic properties opposite of an electron. -
Eugene Goldstein Model
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J.J.Thomson
Studied "canal rays" and found they were associated with the proton H + . And used a CRT to determine the charge to mass ratio (e/m) of an electron =1.759 x 18 coulombs/grams. -
J. J. Thomson Model
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R. A. Millikan
He used the oil drop experiment to determine the charge (e=1.602 x 10 -19 coulomb) and the mass (m = 9.11 x 10 -28 gram) of an electron. -
R. A. Millikan
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Ernest Rutherford
He developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of successive orbital shells of nucleus. -
Ernest Rutherford Model
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Henry Moseley
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Henry Moseley
Used x-ray tubes, to find the charge of the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus". His work was used to change the periodic table by placement of atomic number, not mass. -
Niels Bohr
Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of successive orbital shells of electrons. -
Niels Bohr Model
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Louis de Broglie
Discovered that electrons had a dual nature-similar to both particles and waves. Particle/wave duality. -
Louis de Broglie atomic model
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Erwin Schrodinger
Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom. -
Erwin Schrodinger
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James Chadwick
Used alpha particles and discovered the neutron -
James Chadwick Model
