1.
An ion M2+\text{M}^{2+} forms the complexes [M(H2O)6]2+[\text{M(H}_2\text{O)}_6]^{2+}, [M(en)3]2+[\text{M(en)}_3]^{2+} and [MBr6]4[\text{MBr}_6]^{4-}. Match the complex with the appropriate colour.