As a result of Schottky defect,the density of the crystal:

Calcium crystallises in a face-centred cubic unit cell with edge length $a = 0.556 \ nm$. Calculate the density. If it contained $0.1 \%$ Frenkel defects,what is the density in $g \ cm^{-3}$?

Which of the following statements are not correct?
$(A)$ Diode is a combination of $n$-type and $p$-type semiconductors.
$(B)$ Silicon or germanium is electron rich impurity.
$(C)$ Phosphorus and arsenic are electron deficient impurities.
$(D)$ Schottky defect decreases the density of the crystal.

Which type of defect is observed in crystals like $NaCl$ and $KCl$?

Explain stoichiometric defects shown by non-ionic solids.

Which one of the following crystals does not exhibit Frenkel defect?