Rutherford put forward the model of an atom which had a positively charged center called nucleus. It also had the electrons which revolved around the nucleus in well-defined orbits. He also proposed that the size of the nucleus is very small as compared to the size of the atom and nearly all the mass of an atom is centred in the nucleus. From the data, he also calculated that the radius of the nucleus is about 105 times less than the radius of the atom.

On the other hand, Thomson proposed the model in which an atom consists of a positively charged sphere and the electrons are embedded in it. Both the negative and the positive charges are equal in magnitude. So, the atom as a whole is electrically neutral. Although Thomson’s model explained that atoms are electrically neutral, the results of experiments carried out by other scientists could not be explained by this model.