The Christmas Pudding Model

Well, OK, it's technically called the Plum Pudding Model, but it's the same thing. John Dalton from Cockermouth, just down the road from here, revived the idea of atoms. When JJ Thomson discovered electrons in 1896, that caused a problem. Electrons were negative but atoms were neutral. That meant that there must be positive stuff in the atom. No positive particles had been discovered so the hypothesis was that the electrons were like negative currants in the positive dough of a Christmas pudding. The positive was smeared throughout. This meant a prediction that when positive alpha particles were fired at atoms, there would be no resistance because the positive in the atom was spread out so thinly. Turned out to be wrong ...