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100
Thales
First person to investigate the atom -
100
Democritus
First person to think of an atom. (Cutting the Cheese Thought Experiment) -
100
Aristotle
Didn't believe in the atomic theory but believed in the elements -
Sir Isaac Newton
Discovered that atoms are held together by attractions or forces -
John Dalton
First to have actual proof of an atom through an experiment. (Atomic Theory Experiment) -
Henri Becquerel
Discovered radioactivity (Uranium Experiment) -
J.J. Thompson
Discovered electrons and developed the plum pudding model. (Cathode Ray Tube Experiment) -
Robert Andrews Milliken
Found charge of individual electrons. (Oil Drip Experiment) -
Gold Foil Experiment
Alpha particles fired through a thin gold sheet into a zinc sulfite sheet. -
Ernest Rutherford
Found the nucleus and proton. (Gold Foil Experiment) -
Niels Bohr
Electrons had a certain orbit -
Francis Aston
Discovered isotopes and created the mass spectograph -
Erwin Schrodinger
Used math equations to find the probability an electron would be in a certain place -
James Chadwick
Discovered neutron