Atomic Sturcture_Maresca and Connor

Democritus

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Democritus' Atomic ModelMatter is composed of small particles called "atoms" that could be divided no further. Atoms are indivisible.

Lavoisier

Nov 17, 1789

Law of Conservation of Mass(Matter)He made measurements of a chemical change in a sealed container. Founded the Law of Conservation of Mass.

Proust

Nov 17, 1797

Law of Definite ProportionsHe is a French chemist who founded the Law of Definite Proportion.

Dalton

Nov 17, 1808

Dalton's Atomic Theory

Thomson

Nov 17, 1897

Cathode Ray Tube
He used the cathode ray experiment and found that electrons and protons exist.

Rutherford

Nov 17, 1909

Gold Foil ExperimentPlum Pudding Model
He revised the plum pudding model and the gold foil experiment concluded that atoms must be mostly empty space, they have a small dense center, and the nucleus must be positively charged since alpha particles are positive.

Millikan

Nov 17, 1910

Oil Drop ExperimentRobert A. Millikan was an American experimental physicist, and Nobel laureate in physics for his measurement of the charge on the electron.

Chadwick

Nov 17, 1932

Chadwick's atomic modelChadwick proved the existence of the neutron