-
101
Thales 624 B.C.
Thought all things were made of water -
101
Democritus-- 400 B.C
First person to think of the atom. thought it was a solid sphere. -
101
Aristotle-- 384
Didn't believe in the Atomic Theory. believed all substances were made of fire, water, earth, and air. -
Newton
He agreed with Democritus. -
Dalton
Atomic theory. First to have experimental evidence. -
Henri Becquerel
discovered reactivity, couldn't explain it. -
Joseph John Thompson
discovered the electron -
Ernest Rutherford
discovered the nucleus -
Millikan
Found the charge of an electron -
Niels Bohr
thought electrons orbited around the nucleus -
Erwin Schrodinger
atomic model was the quantum mechanical model. -
James Chadwick
Proved the exsistence of neutrons.