# Aside from neutrons, what else is found in the nucleus of an atom?

Well, the nucleus also contains protons, which are massive nuclear particles each with a formal positive charge. And the number of protons gives $Z$, the atomic number, which number determines the identity of the element: $Z = 1 , H$; $Z = 2 , H e$;..........$Z = 6 , C$;....$Z = 33 , A s$;.....