While writing the formula of ferrous oxide,it is written as $(FeO)$,because it is

The correct statement$(s)$ regarding defects in solids is(are):
$A$. Frenkel defect is usually favoured by a very small difference in the sizes of cation and anion.
$B$. Frenkel defect is a dislocation defect.
$C$. Trapping of an electron in the lattice leads to the formation of $F$-center.
$D$. Schottky defects have no effect on the physical properties of solids.

Electron-deficient impurities are caused by the elements of which group?

In a crystal,Frenkel defect is observed only when the radius ratio is......

In ionic compounds where the sizes of the cation and anion are almost similar,which defect is observed?

Which one of the following has Frenkel defect?