What is the charge that a nitrogen ion will form and explain

A nitrogen atom must gain three electrons to have the same number of electrons as an atom of the following noble gas, neon. Thus, a nitrogen atom will form an anion with three more electrons than protons and a charge of 3−. The symbol for the ion is N3−, and it is called a nitride ion.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.