* Nitrogen's natural charge: Nitrogen (N) is in group 15 of the periodic table, meaning it has 5 valence electrons. To achieve a stable octet, it wants to gain 3 electrons.

* Nitrogen anion: When nitrogen gains 3 electrons, it forms a nitride anion (N³⁻).

* Total charge of two anions: Since each nitride anion has a -3 charge, two nitride anions would have a total charge of -6.

Therefore, the total charge of two nitrogen anions is -6.