ok before chadwick, ppl thought that the nucleus was comprised of only protons. This couldn't be because protons repel each other and so the nucleus couldn't have existed. Chadwick came along with this idea of neutral particles that existed alongside protons. This now accounted for the mass of the atom as a whole, and the stability of the nucleus.
The existence of neutrons was later confirmed experimentally and chadwick takes home the Nobel prize.
~The End~
So C Lol
