The atom will gain 3 electrons
Further explanation
Valence electrons are electrons that are used to bond which are located in the outer shell of the atom
The electron configuration of N :
[He] 2s² 2p³
This configuration shows that there are 5 valence electrons in the outer shell of the N atom
So based on the octet rule, the N atom will bind 3 more electrons to make it stable
An example is the formation of covalent (triple) bonds in the formation of N2 molecules