Atom Timeline By Chloe renee 400 Democritus Oct 5, 1897 thompson plum pudding model Oct 5, 1908 millikan charge of electron Oct 5, 1911 rutherford neucluous and proton Oct 5, 1919 dalton 4 part atomic therory Oct 5, 1922 Bohr electrons orbit the nucleous Oct 5, 1932 Chadwick Neutrons