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

If an electron is present in place of an anion in a crystal lattice,then it is called

Use the appropriate symbols $T$ (True) or $F$ (False) for the following statements regarding defects in solids:
$(1)$ Frenkel defect arises due to the arrangement of cations and anions with a very small difference in size.
$(2)$ Frenkel defect can be called a dislocation defect.
$(3)$ $F$-centers arise due to the migration of electrons released from metal atoms into the crystal lattice.
$(4)$ Physical properties of the crystal do not change due to Schottky defect.

$A$ solid solution of $CdCl_2$ and $AgCl$ exhibits which type of defect?

When $AgCl$ is doped with $10^{-4} \, \text{mole percent}$ $RuCl_3$,what will be the concentration of cationic vacancies per mole of $AgCl$?

Select the incorrect statement for Schottky defect.