-
440 BCE
Democritus
Atoms are uncuttable. Atoms are small, hard partacles. Atoms constantle move. -
440 BCE
Atomic Model
-
John Dalton
All substances are made up of atoms. Atoms of different elements are different. Atoms of the same element are all alike. Elements combine in specific proportians. Conducted expirements in combining elements. -
Dalton atomic model
-
Thomson model
-
J.J. Thomson
He conducted the cathode-ray tube experiment. His theory of the atomic structure lead to the "plum pudding” model. There are small, negatively charged particles inside an atom. -
Ernest Rutherford
Electrons move in empty space in the atom. He conducted the gold foil experiment. Most of an atoms mass is in the nucleus. There is a small, dense, positively charge nucleus. -
Rutherford model
-
Erwin Schrödinger & Werner Heisenberg
Electron paths cannot be predicted. Electrons are found in electron clouds, not paths. -
Schrödinfer & Heisenberg model
