ABSTRACT
"Plum pudding" model, where electrons were analogous to raisins in a fluffy positively charged cake, explained the electrical neutrality of the atom – the sum of the electrons' negative charges matched the total positive charge. The plum pudding model suggested an easily interpretable experiment: a beam of alpha particles from an alpha emitter should pass right through the plum pudding with little bending of the beam. An alpha particle incident on a plum pudding-type of atom would experience little electrical repulsion from the atom's diffuse positive cloud and would easily bump aside the much less massive electrons. Thus, the alpha particle should experience little deflection while traversing a group of plum pudding-type atoms. The inability of alpha particles to penetrate very far into matter, such as the gold foil in Rutherford's experiment, is due to the high rate at which they deposit energy in their wake.
