Question

Transition metals have the electronic configuration $\left(n-1\right)d^{1-10}\,ns^{1-2}$ . The $d$ -orbitals are degenerate. Colour of transition metal ions is due to absorption of some wavelength. This results is

• A. d - s transition
• B. s - d transition
• C. s - s transition
• D. d - d transition

Answer 1

Answer: (D)

When a transition metal compound is formed, the degeneracy of $d$ -orbitals is resolved giving two sets of orbitals slightly differing in energy. Absorption of light causes the promotion of electrons from lower energy set of orbitals to higher energy set within the same $d$ -subshell. This is called $d$ - $d$ transition.