Write the formula and give the name for the compound formed by the ions
a) Cr³⁺ and F⁻
b) Cu²⁺ and Br⁻
c) Fe²⁺ and O²⁻
d) Pb²⁺ and Cl⁻
e) Hg²⁺ and S²⁻
f) Sn²⁺ and F⁻
g) Fe³⁺ and O²⁻