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

Schottky defect defines imperfection in the lattice structure of a

Analysis of the density of an electrically neutral $NaCl$ crystal containing vacancies yielded the following results:
$(i)$ Density of $NaCl$ crystal with all sites occupied $= 2.178 \times 10^3 \ kg \ m^{-3}$
$(ii)$ Density of $NaCl$ crystal with vacancies $= 2.165 \times 10^3 \ kg \ m^{-3}$
Then the percentage of vacancies in the $NaCl$ crystal is .....

The defect that arises when smaller cations move into interstitial sites in a crystal lattice is known as ..............

$A$ metal oxide shows $p-$type semiconductivity. The conductivity of the oxide will increase by:

Which defect causes a decrease in the density of a crystal?