-
101
Thales 624
No experiments, everything was made from water -
101
Democritus 400 B.C.
Theoetical thinkning. Advanced hypothesis that all matter was made up of atoms -
101
Aristotle 322 B.C
Did not believe in the atomic therory all substances were made of fire,water,earth, and air -
Issac Newton
No experiements -
Dalton 1844
Atomic theory, first to have experimental evidence. Law of fixed proportions. -
Henri Becquerel 1896
Discovered reactivity, could not explain it though. -
Joseph John Thompson 1897
Discovered the electron. Cathode Ray Experiments- 2 metal ends in a tube hooked up to a battery. -
Ernest Rutherford 1903
Discovered the nucleus, gold foil experiement -
Millikan 1912
OIl drop experiement. Found the energy of an electron. -
Niels Bohr 1916
Created the Bohr model. Thought electrons orbitted around the nucleus -
Erwin Schrodinger 1926
Atomic model was the quanum mechanical model. Proved Bohr's model wrong. Preduces the odds of the electron location. -
James Chadwick 1932
proved the existence of neutron