Answer:
+3
Explanation:
Let's consider the chemical formula XN. It must be formed by a cation coming from X and an anion coming from N. Nitrogen has only one negative charge: -3. We know, that the sum of the charges of the elements that form a compound is equal to the charge of the compound. considering XN is a neutral compound (charge 0), we can use this information to calculate the charge of X.
X + N = 0
X + (-3) = 0
X = +3
