history of the atom

john Dalton 1800s - atoms are solid spheres

jj thompson 1897 - plum pudding model - ball of positive charge with negative electrons studded into it

rutherford 1909 - nuclear model fired alpha particles at a thin sheet of gold and some were deflected and did not go straight through. also believed that the negative particles were a cloud around the positive ball

niels bohr 1913 - electrons orbit in shells

rutherford - protons

james chadwick - neutrons