write the empirical formula of at least four binary ionic compounds that could be formed from the following ions Ca2+,Ni4+,Cl-S2-?

CaCl₂
CaS
NiCl₄
NiS₂

The four compounds are calcium chloride, calcium sulfide, nickel chloride, and nickel sulfide. To write the empirical formula, the total positive charge must be equal to the total negative charge.

#1 = CaCl2
#2 = CaS
#3 = NiCl4
#4 – NiS2

I hope this is helpful for you.