Question

Give the formulas for the ionic compounds made of the following ions:

Sc3+ and Br¯
K+ and O2¯
Ca2+ and I¯
Cr3+ and S2¯
Rb+ and F¯
magnesium (Mg) and oxygen (O) ions
potassium (K) and nitrogen (N) ions
strontium (Sr) and fluorine (F) ions
aluminum (Al) and sulfur (S) ions

Answer 1

ScBr3, K2O, CaI2, Cr2S3, RbF, MgO, K3N, SrF2, and Al2S3. The only thing you need to do is to ensure every ionic compound has a total valence of zero. Four the last four, you need to know usually valence of these ions.