The formula for Tin(II) Nitride is Sn3N2.
To understand why this is the case, we need to break down the components of the compound. Tin (Sn) can have multiple oxidation states, and in this case, we are looking at Tin(II), which means that tin has a +2 oxidation state. Nitrogen (N) generally has a -3 oxidation state.
In order to balance the charges between tin and nitrogen in the compound, we need three tin cations to balance the two nitride anions. This results in the overall formula of Sn3N2. Therefore, when combining these ions, we get the stoichiometry reflected in the formula Sn3N2.