Atomic Theory

Democritus

370

Greek philosopher, and Believed that the universe was made of tiny "Uncuttable" Paricles

John Dalton

Mar 15, 1803

Hypothesized that the atom was a tiny hard sphere, and Belived that the atoms of a given element are identical.

JJ Thomson

Mar 16, 1897

Discovered the electron, Used the cathode ray tube in his discovery, Created the "plum pudding" Model of the atom

Ernest Rutherford

Mar 16, 1911

Did the gold foil experiment, Discovered that the proton had a positive charge, and discovered that the stom is mostly empty space

Niels Bohr

Mar 16, 1915

Created a model of the atom with elecrtons moving around the nucleus in fixed orbits, and

Werner Heisenberg

Mar 15, 1925

Worked with the Quantum Theory, and Uncertainty principle a Particle's postion, energy, and time can never be Known

James Chadwick

Mar 16, 1932

Discovered the neutron, and Found the missing mass of the atom's nucleus