# What is the subatomic particle that determines the name of an atom?

The identity of the element is determined by the number of protons, which are positively charged, massive nuclear particles. The number of protons in a nucleus is given by $Z$, the atomic number.
For $Z = 1$, the element is $H$; $Z = 2$, the element is $H e$; $Z = 3$, the element is $L i$........................$Z = 78$, the element is $P t$. Of course, each atom may contain various numbers of neutrons, massive, neutrally charge nuclear particles; the which give rise to the existence of isotopes.