(A) The sizes of the atoms in Thomson's model and Rutherford's model are of the same order of magnitude,so the correct choice is 'no different from'.
$(b)$ In the ground state of Thomson's model,the electrons are in stable equilibrium. In Rutherford's model,the electrons are in motion and always experience a net force.
$(c)$ $A$ classical atom based on Rutherford's model is doomed to collapse because the revolving electrons would continuously radiate energy and spiral into the nucleus.
$(d)$ An atom has a nearly continuous mass distribution in Thomson's model (the plum pudding model),but has a highly non-uniform mass distribution in Rutherford's model (concentrated in the nucleus).
$(e)$ The positively charged part of the atom possesses most of the mass in both the models.