Which of the following statements is wrong regarding Lanthanoids?

Options

A. Ln(III) compounds are predominantly ionic in character.
B. Ln(III) hydroxides are mainly basic in nature
C. The ionic size of Ln(IIl) ions decreases with increasing atomic number
D. Ln(III) compounds are generally colourless.

Answer

D

Explanation

Many of the trivalent ions of lanthanoids are coloured, both in the solid state as well as in solution. The colour of lanthanoid ions arises due to absorption of light from visible region of spectrum resulting in f-ftransitions as lanthanoids have partly filled f-orbitals.