Which is the incorrect statement ?

Question

$\begin{array}{1 1} (1) FeO_{0.98} \text{has non stoichiometric metal deficienry defect} \\ \text{(2) Density decreases in case of crystals with Schottky's defect.} \\ (3) NaCI(G) \text{is insulator, silicon is semiconductor, silver is conductor, quartz is piezo electric crystal.} \\ \text{(3) Frenkel defect is favoured in those ionic compounds in which sizes of cation and aniors are almost equal.} \end{array}$