Give examples of displacement defects in solids.

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

State the types of point defects.

Iron crystallizes in $FCC$ with an edge length of $400 \ pm$. If it contains $0.1 \%$ Schottky defects, calculate its approximate density $[AW \text{ of } Fe = 56 \ g/mol]$. (in $g/cm^3$)

When $NaCl$ (molten) is doped with $10^{-5} \, mol \, \%$ of $AlCl_3$,what is the concentration of cation vacancies?

Frenkel and Schottky defects are