Suppose you made up your own 'atom', as Thomson described, using clay for the positive charge and small beads for the electrons spread through it. What will happen if:

(A) the positive charge on the clay is lesser than the total negative charge of the beads?

(B) by mistake, the clay itself carries a bit of negative charge? Would your model still represent a neutral atom? [Pg. No. 143]

In Thomson’s atomic model, the atom is neutral because the total positive charge is equal to the total negative charge of the
electrons embedded in it.
(A) If the positive charge on the clay is lesser than the total negative charge of the beads, the model will have an overall negative charge. So, it would not represent a neutral atom; instead, it would represent a negatively charged particle or ion.

(B) If the clay itself carries some negative charge, then the total negative charge of the model increases. The model will still be neutral only if the total positive charge of the clay is exactly equal to the total negative charge of the beads plus the extra negative charge on the clay. Otherwise, it will not represent a neutral atom. Also, this would not properly match Thomson's model, because in his model the clay-like sphere represents only positive charge, with electrons embedded in it.