Scientist time line

John Dalton

Sep 3, 1803

John Dalton used prior knowledge from scientist to come up the the atomic theory. his conclustion was matter is made up of tomes, atoms in elements are identical, and atoms can be rearanged

George Stoney

Nov 17, 1874

Stoney established a basic understanding of electricity as early as 1874

J.J Thompson

Apr 30, 1897

J.J thompson used cathode rays putting them in a glass tube. He applied electicty to both ends. When he got a negative charged he discoverd the electron.

Niels Bohr

Oct 16, 1913

Bohr discovered electrons can only be a certain distance from the nucleus. If its close to the nucleus its at its lower level. This showed how an atom could gain and loose electrons. He also came up with the composition of electricity.

Ernest Rutherford

Jun 3, 1920

Ernest Rutherford used gold foil and alpha particles. He shot the positive particles at the foil.Some deflected and some passed through. his conclustion was the nucleus was positively charged and the atom has empty space around the center.

James Chadwick

Feb 7, 1932

James Chadwick found the beam wasnt deflected in Rutherford's experiment by eletic feilds. the particles had no charge. they were neutral, thus discovering neutrons. Atoms had a neural charge.

Murray Gell-Mann

Aug 17, 1960

Gell- Mann discovered protons and neutrons are made up of even smaller particles called quarks and leptons. they were found by observing high energy nuclear collisions. Each quark type is known as a flovor. There are 6, up, down, bottom, top,strange, and charm.