Question

Zn salts are white but cu salts are colored .Why

Answer 1

$\huge\bold{\boxed{\mathtt{\red{Answer}}}}$

The colours of salts of transition metals are due to the d-d transition that depends on the presence of incompletely filled d-orbitals. Zn2+ has completely filled d-orbitals (3d10), while Cu2+ has incompletely filled d-orbitals (3d9); therefore, d-d transition is possible in Cu2+, which imparts colour to copper (II) salts.