State the types of point defects.

$NaCl$ is heated in an atmosphere of sodium vapour. The resultant yellow colour is due to the formation of

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

How do defects arise in crystals? State the types of defects.

$1 \ \text{mole}$ of $NaCl$ is doped with $10^{-5} \ \text{mole}$ of $SrCl_{2}$. The number of cationic vacancies in the crystal lattice will be:

If $NaCl$ is doped with $10^{-3} \, mol \% \, SrCl_2$,what will be the concentration of cation vacancies?