Question

Write formulas for compounds formed from these pairs of ions:
1. Ba2+, S2-
2. B. Li+, O2-
3. Ca2+, N3-
4. Cu2+, I-

Answer 1

1. BaS
2. Li2O
3. Ca3N2
4.CuI2

Answer 2

The formulas for compounds formed from these pairs of ions are as follows:

1. Ba2+, S2- 

BaS, 1 atom of Ba2+ is needed to have a stable compound with S2- .


2. Li+, O2- 

Li2O, 2 atoms of Li+ is needed to have a stable compound with O2- .

3. Ca2+, N3- 

Ca3N2,  3 atoms of Ca2+ is needed to have a stable compound with 2 atoms of N3- .

4. Cu2+, I-

CuI2,  1 atom of Cu2+ is needed to have a stable compound with 2 atoms of I- .