# Atoms of which element have two protons and two electrons?

If the atom has $\text{2 nucular protons}$, the atom is ...........
If the atom has $\text{2 nucular protons}$, the atom is $\text{helium.}$
The identity of the atom is determined by its atomic number, $Z$, which is equal to the number of massive, positively charged particles, $\text{protons}$, that its nucleus contains. $Z = 1$, the atom is $\text{hydrogen}$; $Z = 2$, the atom is $\text{HELIUM}$; $Z = 3$, the atom is $\text{lithium}$;...................