Wich is the incorrect statement?

Options

A. `FeO_(0.98)` has non stoichiometric metal deficiency defect
B. Density decreases in case of crystals with Schottky's defect
C. NaCl(s) is insulator, silicon is semiconductor, silver is conductor, quartz is piezo electric crystal
D. Frenkel defect is favoured in those ionic compounds in which sizes of cation and anions are almost equal

Answer

A, D

Explanation

Frenkel defect occurs in those ionic compounds in which size of cation and anion is largely different.
Non-stoichiometric ferrous oxide is `Fe_(0.93–0.96)O_(1.00)` and it is due to metal deficiency defect