Atomic Theory Theorists

Theorists

Democritus

442 B.C.

John Dalton

1803

JJ Thompson

1898

Ernest Rutherford

1909

Niels Bohr

1913

Erwin Schrodinger

1926

James Chadwick

1931

Specific Experiments for Theorists

Matter is Made of Indivisible Particles

442 B.C.

Experiments with gas mixtures

1803

Sees how the properties of an individual gas affect the mixture

Four Atomic Postulates

1803

Atoms are indestructible; atoms of same element are the same; atoms combine to make simple whole number ratios; atoms reorganize during a chemical reaction

Wanted to Prove What Electrons Were

1897

Accomplished this with the cathode rays from cathode

Gold Foil Experiment

1911

Discovered radiation by using thin pieces of metal to see the absorption of radioactivity in the metal sheets

Discovered the Structure of the Atom: Bohr Model

1913

When Radiation is Emitted from the Atom

1916 - 1920

There is a Proton and Neutral Particle in Atoms

1920

Papers Written about Quantum Mechanics and Molecules

1926

Electron Cloud Model

1926

Beryllium got Bombarded by Radiation

1930

The Neutron is Officially Discovered

1932