The correct statement regarding defects in crystalline solid is

a. Schottky defects have no effect on the density of crystalline solids

b. Frenkel defects decrease the density of crystalline solids

c. Frenkel defect is a dislocation defect

d. Frenkel defect is found in halides of alkaline metals.

Ans. c

Explanation : Frankel defect occurs when the cations are missing from their lattice sites, occupy intersitial sites. So It is a  dislocation defect. Density remains unchanged. Size of cations should be small as compared to size of anion. So it is not found in helides of alkaline metals.