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400
460 BC Democritus
Democritus develops the idea of atoms -
John Dalton
John Dalton came up with the first experiment that matter was made up of tiny particles -
JJ Thompson discovers that atoms have electrons
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Ernest Rutherford
Conducted his gold foil experiment where he fired helium nuclei and discovered about 1 in every 10,000 nuclei hit the gold foil -
Bohr refines Rutherford
Bohr refines Rutherford's experiment by adding that electrons were in orbit around the nuclei -
Jimmy Chadwick
discovered that the nucleus had protons and neutrons
