Untitled timeline



460 B.C. - 370 B.C.

Democritus was a Greek scientist that hypothesized the existence of atoms and their being indivisible and indestructable.


384 B.C. - 322 B.C.

Aristotle was a Greek scientist that rejected Democritus' idea as he thought that matter was continuous.

John Dalton

1766 - 1844

Dalton was a English scientist that came up with the atomic theory

William Crookes

1832 - 1919

Crookes was a British scientist that developed the cathode ray tube

JJ Thompson

1856 - 1940

Thompson was a British scientist that showed that the "cathode ray" which traveled from cathode(-) to anode (+) was electrons in 1897. Thompson also discovered electrons and developed the plum pudding model.

Robert Millikan

1863 - 1953

Millikan was an American scientist that found the charge on an electron to be 1.602 x 10^ -19 Coulobmbs and found the mass of an electron to be 9.11 x 10^ -28

Ernest Rutherford

1871 - 1937

Rutherford was an English scientist that conducted the gold foil experiment which led to the concept of the nucleus. Therefore, Rutherford discovered the nucleus and also developed the nuclear model.

Neils Bohr

1885 - 1962

Bohr was a Danish scientist that found that hydrogen absorbs energy then releases it at a specific frequency

Henry Moseley

1887 - 1915

Moseley was an English scientist that found that atoms have a special and unique charge

James Chadwick

1891 - 1974

Chadwick was an English scientist that discovered the existence of neutrons.