Answer:
Option C = three electrons are gained, making N⁻³
Step-by-step explanation:
Nitrogen is present in group 5A.
Its atomic number is seven.
It have five valance electrons.
Its electronic configuration is N₇ = [He] 2s² 2p³
In order to complete the valance shell or 2p subshell nitrogen must gain three more electrons.
When an atom gain the electrons anions are formed and negative charge is created on it.
When an atom lose its valance electrons cation is formed and positive charge is created.
That's why when nitrogen gain three electrons to complete the valance shell N⁻³ is formed.