Here's why:

* Manganese (Mn) is a transition metal with a variable oxidation state.

* Nitrogen (N) typically has an oxidation state of -3 in its compounds.

To balance the charges, the correct formula for manganese nitride is Mn₃N₂. This formula represents a neutral compound with three manganese ions (Mn³⁺) and two nitride ions (N³⁻).