The hexaaqua complex`[Ni(H_(2)O)_(6)]^(2+)` is green, whereas the corresponding ammonia complex `[Ni(NH_(3))_(6)]^(2+)` is violet. Explain.

Explanation

`NH_(3)` is a stronger ligand than `H_(2)O`, SO `[Ni(NH_(3))]^(2+)` will absorb higher energy light than `[Ni(H_(2)O)_(6)]^(2+)`. Being green, `[Ni(H_(2)O)_(6)]^(2+)` is probably absorbing higher energy yellow green light