Atomic Theory

Events

Robert Boyle

1662

discovered that atoms must exist based on the relationship between pressure and temperature.

Joseph Priestley

1774

discovered oxygen

Carl Scheele

1777

Discovered that oxygen is present in the air

Antoine Lavoisier

1785

discovered the law of conservation

Joseph Proust

1794

discovered the law of constant

John Dalton

1803

created the atomic theory that we still use today

Julius Plücker

1858

used cathode ray tubes to help discover the electron

William Crookes

1875

Invented the Crookes tube in 1875 which showed evidence of electron streams

J. J. Tomson

1897

Used cathode ray tubes to help discover electrons in 1897

Pierre and Marie Curie

1898

discovered the elements radium and polonium in 1898

Hans Geiger

1908

Helped discover the atomic nucleus in 1908

Robert Millikan

1908

discovered the charge of an electron in 1908

Jean Baptiste Perrin

1908

Confirmed that all matter was comprised of atoms

Ernest Rutherford

1911

overturned Thomson's model of the atom in 1911 with the gold foil experiment.

James Chadwick

1932

discovered the neutron in 1932.