Answer:
N³⁻ contain seven protons and ten electrons.
Explanation:
Nitrogen have seven protons and seven electrons. When it an atom lose or gain the electrons ions are formed.
Cation:
When an atom lose the electrons the formed is called cation.
e.g Na⁺ sodium lose one electron and form cation.
Anion:
when an atom gain the electrons the ions formed is called anion.
e.g N³⁻
Nitrogen consist of seven electrons and seven protons. when it gain electrons anions are formed. In given symbol nitrogen consist of 3- charge which means nitrogen gain three more electrons so total electrons will be ten.