Select the incorrect statement `:`

Options

A. Stoichiometry of crystal remains uneffected due to Schottky defect.
B. Frenkel defect usually shown by ionic compounds havin low coordination number.
C. `F-` centres generation is responsible factor for imparting the colour to the crystal
D. Density of crystal always increases due to substitutional impurity defect.

Answer

4

Explanation

Density of crystal always increases due to substitutional impurity defect.