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Sep 2, 1001
Aristotle
Matter is described by the following
Earth (Solid)
Water (Liquid)
Fire (Energy)
Air (Gas) -
Crookes
Cathode Ray Tube (CRT)
Generates electrons -
Dalton
Discoverd elements & compounds -
Henri Becquerel
Discovered radioactivity
Radiation produced spontaneously by unstable atomic nucleus -
Thomson
Discovered electrons
Plum Pudding or (chocolate chip) model -
Rutherford
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Bohr
Electrons orbit in energy levels around the protons in the nucleus
Model of the atom looks like a solar system -
James Chadwick
Identified neutron
Same mass as proton
No charge
