Which of the following statements for crystals having Frenkel defect is /are not correct?

Options

A. Frenkel defect are observed where the difference in sizes of cation and anions is large
B. The density of cystal having Frenkel defect is lesser than that of a pure perfect crystal
C. In an ionic crystal having Frenkel defect may also contain Schottky defect
D. Pure alkali halides do not have Frenkel defect

Answer

B

Explanation

The density of crystal have have Frenkel defect is identical to that of pure crystal.