Thomas Moretz By thomas888 200 440 BCE-Democritus His theory was if kept dividing something you would get to some thing which can't be divided. He called this an atom. 201 382 BCE-Aristotle Aristotle belived that particles could be infinety cut. Jan 1, 1803 Dalton Dalton thought that atoms of the same element are exactly alike. Jan 1, 1897 Thomson Thomson thought electrons were mixed thoughout the atom like "plums in pudding." Jan 1, 1909 Rutherford-1909 Rutherford conducted an experiment in which he shot particles on a thin sheet of gold. to his suprise some bounced back. Jan 1, 1911 Rutherford-1911 Rutherford created a model in which eletrons circle a dence center called the nuculous. Jan 1, 1913 Bohr Bohr though that electrons rotated around the nuculous in certain paths. Jan 1, 1950 Schrodinger and Heisenberg Schrodinger and Heisenberg consructed a model which introduced electron clouds. electron clouds are places were the electron is likely to be found.