-
Thales- 600BC
Everything is made out of something -
Democritus- 460BC
Things are made of atoms -
Aristotle- 322BC
Didn't believe in the atomic theory -
Sir Isaac Newton
all atoms move around and are really small -
Dalton- 1803
came up with the atomic thoery -
Becquerel- 1896
discovered radioactivity -
Thomson- 1896
discovered electron -
Millikan
determined charge and mass of electron -
Bohr
discovered that electrons move on a fixed path around the nucleus (false) -
Aston
discovered isotopes -
Schrodinger
was able to calculate where an electron would probably be with electron clouds -
Chadwick
discovered evidence toward existance of neutrons