what is mean by nuclear theory?

Question

its related to chemistry?

Answer 1

"Nuclear theory" refers to the idea that the mass of the atom is found in the nucleus only. The electrons are too small to add to the mass. Rutherford and his students did the "gold foil" experiment and determined that all atoms have a tiny, dense nucleus at the center and the electrons orbit around at a great distance.

The study of the nucleus is known as "nuclear chemistry" or "nuclear physics."

Answer 2

Basic is E = MC2. For full theory please go for a search engine.