-
400
Aristole BC
-Relieved in the four elements of air, earth, water, fire
-He had no method -
460
Democritus BC
- Matter could not be divideed into smaller pieces -He used his ideas
-
Dalton
-All matter is made of atom
-He proposed the Atomiv theory of matter based on his experimental observations -
Rutherford
-he discovered nucleus
-the atom has a positive nucleus with negative electrons orbiting around it -
Bohr
-a new atom model that would allow the electrons to be outside the nucleus and in orbit around the nuclues
-the electrons were on a orbit -
Heisnberg and Schrodinger
-an equation
-electrons move when in an atom -
Thomson
-the electron using the cathode-ray tube
-a mass spectrograph which found isotopes
