Chemistry - Complete d-block Question with Solution | TestHub

The colour of transition metal ions is due to$\text{d-d}$transition. When a ligand approaches metal ion, its$\text{d}$-orbital does not remains degenerate.

They split into two sets, one consisting of lower energy and the other consisting higher energy level.

Thus electrons can jump from lower energy$\text{d}$-orbitals to higher energy$\text{d}$-orbitals. Such transition are known as$\text{d-d}$transition.

The required amount of energy during$\text{d-d}$transition is obtained by absorption of light of a particular wavelength in the region of visible light.

Note:Sometimes the colour of transition metal ions is also due to charge transfer spectra.