Transition metals form mostly coloured compounds.Explain.

Explanation

The colour of the compounds of transition metals may be attributed due to the presence of incompfote (n - 1) d subshell. In the case of compounds of transition metals, the energies of five d-orbitals in the same subshell do not remain equal. Under the Influence of approaching ions (ligands) towards the central ion, the d-orbitals of the central metal split into different energy levels. This Phenomenon is called Crystal field splitting. In the case the transition metal ions, the electrons can be easily promoted from one energy level to another in the same d-subshell. These are called d-d transition.