a. Copper has a valency of 2.
It is a metal and thus forms a cation by losing two electrons, Cu2+.
Sulphate is an polyanion with a valency of 2.
Formula of compound = CuSO4
b. Copper has a valency of 2.
It is a metal and thus forms a cation by losing two electrons, Cu2+.
Cl forms an anion by gaining one electron.
Formula of compound = CuCl2