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Democritus
Greek philosipher, who developed the atomic theory of the universe. The Atomic theory created the principles of the concervation of energy and matter. -
John Dalton
Proposed the Atomic theory with solic spherical atoms based apon measurable properties of mass. -
Henri Becquerel
While studying the effect of x-rays on photographic phil, he discovered some chemicals give off very penetrating rays. -
Marie & pierre
French chemists that discovered the uranium rays. there experements eventually lead to connections with the Atom. -
J.J Thompson
created a model of the Atom.
British chemest Joseph john Thompson discovered the electron in a series of experaments desighned to study the nature of electric discharge in a high-vacuume cathode-ray tube. -
Robert Millikan
American physicist, best known for his work in atomic physics and major science. He with the fundimental constituents of the universe, the forces they exert on one another, and the results produced by these forces. -
Ernest Rutherford
British physicist, who became a nobel laureate for the theory of the structure of the atom. He established the thought that the nucleous was very dense, very small ans posatively charged. He also assumed that the electrons were located outside the nucleus. -
Neils Bohr
Developed an explination of atomic structure that underlies regularities of the periodic tableof elements. His atomic model had atoms built up of successive shells of electrons. -
James Chadwick
Using alpha particles discovered a neutral atomic particlewith za mass close to a proton. Then discovered the neutron and measured the energy of the protons emerging from the hydrogen atoms. -
Aristotle
The most important Greek philosipher of his time introduced the theory of the atom. -
Period: to
Time Line of the Atomic Theory
starting from 384 B.C ending at 1932.