Atomic Theory

1897

1803

Claimed that electrons were not inside the proton, but outside. He used the gold foil experiment to coclude is theory.

1913

John Dalton

Important Dates

370 B.C

1911

1910

Atomic Theory

1932

1936

He claimed that allmatter was made up of atoms. Atoms were invisible and indestructible. All atoms of a given element are identical in mass and properties. Dalton dedicated his life to experimenting with gases

Claimed atoms were small, hard particles that were made of the same material, but had different shapes and sizes.

Democritus

Ernest Rutherford

Claimed that atoms were made of electrons. He used the cathode ray experiment to form his model called plum pudding model.

JJ Thomson

He claimed that there was a charge in every particle in the atom. He used the oil drop experiment to find his theory.

Robert Millikman

Claimed that electrons could only occupy certain orbits or shells in an atom. Bohr studied with prisms and light his life to conclude his theory.

Neils Bohr

Claimed that electrons confined in their orbits would set up standing waves. Schrodinger did not do a experiment, but athought experiment about a cat in a bunker with radioactive material.

Erwin Schrodinger

He predicted that atoms had another particle, the neutron. Also he established that the atomic number is determined by the number of protons

James Chadwick