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101
Thales 600 BC
Cosmological Thesis, everything is made out of water -
101
Democritus 400 BC
Matters smallest piece is an atom. -
101
Aristotle 400 BC
Believed everything was comprised of the four main elements. -
SIr Isaac Newton
Backed Democritus's theory of the atom. -
Dalton
Atomic theory of matter. -
Antoine Henry Becquerel
Discovered radioactivity. -
JJ Thompson
Discovered electron, cathode ray tube experiment. -
Robert Milikan
Oil drop experiment which determined mass of electrons and charge. Changed model to the plum pudding model. -
Rutherford
Gold foil experiment to find the nucleous. -
Niels Bohr
Found that electrons orbit the nucleous. -
Francis Aston
Discorved isotopes. -
Erwin Schrodinger
Created electron clouds. -
James Chadwick
Found neutron.