The plum pudding model of the atom by the scientist Sir Joseph John Thompson or J.J. Thompson. It was theorized after the discovery that electrons are present in the atom. In this model, the atom is composed mainly of electrons. It was describe as plum pudding because the electrons are dispersed within the atom. John Dalton discovered the atom. Ernest Rutherford discovered the half – life of an atom and Neils Bohr explain the quantum mechanics. So the answer is J.J. Thompson.
