Explanation:
An atom consists of three type of sub-atomic particles these are protons, neutrons and electrons.
Protons hold a positive charge whereas neutrons have no charge. On the other hand, electrons are negatively charged.
Both protons and neutrons reside inside the nucleus of an atom and electrons revolve around the nucleus of the atom.
Hence, we can conclude that nucleus is the name of region of the atom where protons and neutrons are located. And, orbital or shells is the region of the atom where electrons are located.
