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370
Democritus
In 370 B.C.
Democritus was the first really scientict ever, and sugguested the existance of atoms -
Newton
Thought the atom was a dot, and thought Democritus was correct after a lot of people didn't think so -
John Dalton
Used Dalton's Atomic Theory
1.All the elements are composed of the atoms
2. Atoms of the same element are identical, atoms of the different elements are different
3.Atoms form compunds
4. Atoms are rearranged, not created or destoryed in a chemical reaction -
Dmitri Mendeleev
Created first periodic table. He organized it by weight -
J. J Thomson
discovered the electron, he called his model THe Plum Pudding Model. He used the Cothode Ray Tube to help prove this -
Erinie Rutherford
He used the gold foil experiment to prove that the nucleus of the atom has a positive charge and the electrons orbit the core -
Planck
He showed that when you vibrate an atom hard enought you can measure the energy -
Niels Bohr
That eletrons are orbiting on tracks, and are on differnt energy fields -
Einstein
E=mc2 -
Milikan
Used the oil drop experiment. He also found mass of the protons and the charge of the electrons. He used the same model has Bohr -
Clound Model
Electrons do not orbit on neat rings, but could be anywhere -
Chadwick
he discovered the neutron