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Q.
Transition elements form coloured ions due to
The d-and f-Block Elements
Solution:
Transition elements form coloured ions due to $d-d$ transitions. In the presence of ligands, there is splitting of energy levels of $d$-orbitals. They no longer remain degenerated. So, electronic transition may occur between two $d$-orbitals. The required amount of energy to do this is obtained by absorption of light of a particular wavelength in the region of visible light.