Atomic Model Timeline

Democritus's Atomic Model

460

Democritus had an idea of atoms but in a void.

Dalton's Atomic Model

Oct 30, 1803

Dalton believed that all matter is made out of atoms and that theya re invisible and indestructible.

Michael Faraday

Jan 1, 1832

Michael Faraday verified that electrical forced held together an atom.

J. Plucker

Jan 1, 1858

Julius Plucker built one of the first gas discharge tubes also known as a cathode ray tube.

William Conrad Roentgen

Oct 28, 1895

William discovered X-rays while using the cathode ray tube.

J.J Thomson

Oct 29, 1897

He discovered the Plum pudding model of the atom and he concluded that there are electrons around the atom surrounded by a positive charged area to blance out.

Hantaro Nagaoka

Oct 29, 1904

He discovered a planetary model of the atom based on saturn's rings but this model was incorrect.

Ernest Rutherford

Oct 31, 1911

Rutherford theorized that atoms have a small positive charge in a small nucleus. He tested this theory with the gold foil experiment and he came up with a new model.

Niels Bohr

Oct 31, 1913

He believed that outer orbitals could hold more electrons then inner orbitals. He also suggested that the outer orbitals determine the atom's chemical property.

Cockcroft & Walton

Oct 31, 1929

They built an accelerator and bombarded lithium with protons to make alpha particles

Schrodinger

Oct 31, 1930

Saw electrons as a continuous clouds and introduced wave mechanics as a mathmatical model of an atom.

Enrico Fermi

Oct 31, 1942

He did the first controlled chain reaction releasing energy from the atom's nucleus.