Question

The tendency of the transition elements to form coloured compound is attributed to:

• A. transition of electrons from one atom to the other.
• B. transition of electrons from 5-orbitals of the outer shells to p-orbitals.
• C. d-d transition of electron in last but one shell.
• D. none of the reason is correct.

Answer 1

Answer: (C)

According to crystal field theory the colour o f the complex is due to the d-d transition of the electron in presence of ligands. For example, in${\left[Ti\left(H_2{O}_6\right)\right]}^{3+}$ by absorbing green yellow component of white light, d-d transition of electron takes place and the aqueous solution appears purple as the purple is the complimentary colour of greenish-yellow.