Question

How to find chemical formula for copper ii nitride?

Answer 1

We know that Copper ll 's symbol is $Cu^{+2}$ and Nitride's is $N^{-2}$

Because both have opposite charges of +2 and -2, they both cancel out when written. When writing a chemical formula, the cation (positive ion/element) is written before the anion (negative ion). The formula name already had the correct order. Therefore, your chemical formula is just CuN

Hope this helps!