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460 BCE
Democritus
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Period: 460 BCE to 370 BCE
Democritus
. Came up with the base idea of atoms
. Found out that atoms constantly move
. Concluded that atoms of different elements are different
. Concluded that atoms of the same element are exactly alike -
John Dalton
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Period: to
John Dalton
. Concluded that all matter is made of atoms
. All atoms of a given element are identical in mass and properties
. -
J.J. Thomson
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Period: to
J.J. Thomson
. Conducted the cathode-ray tube experiment
. Proposed the plum pudding model of the atom
. Discovered electrons (Negatively charged particles) -
Ernest Rutherford
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Period: to
Ernest Rutherford
. Discovered that atoms are mostly empty space
. Conducted the gold foil experiment
. Discovered two types of radiation -
Niels Bohr
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Period: to
Niels Bohr
. Electrons move around the nucleus in prescribed orbits -
Period: to
Erwin Schrӧdinger and Werner Heisenberg
. They invented the new quantum theory of physics
. -
Erwin Schrӧdinger and Werner Heisenberg
