atomic theory time line

Democrtus

460

460-370B.C. was the first person to propose the idea that matter was not infinetly divisible.

Cathode Ray Tube

Oct 23, 1800

the accidental discovery of the cathode ray led to the invention of the most important technological and social developments of the 20th century-the television. Scientists continued their research using cathode ray tube and by the end of the 1800's they were fairly convinced.

John Dalton

Oct 23, 1844

A school teacher in England, marks the beginning of the development of modern atomic theory.

J.J. Thompson

Oct 23, 1890

He began a series of cathode ray tube experiments in the 1890's to determine the ratio of its charge to its mass.

Ernest Rutherford

Oct 23, 1899

he discovered the radio activity

Robert Millikan

Oct 23, 1909

american physicts, determined the charge of an electron