Match List-I with List-II

List-I (Defects)	List-II (Shown by)
a) Frenkel defect	i) Non-ionic solids and density of the solid decreases
b) Schottky defect	ii) Non-ionic solids and density of the solid increases
c) Vacancy defect	iii) Ionic solids and density of the solid decreases
d) Interstitial defect	iv) Ionic solid and density of the solid remains constant

Choose the correct answer from the options given below:

. Frenkel defect : It is  shown by ionic solids. The smaller ion (usually cation) is dislocated from its normal site to an interstitial site. It does not change the density of the solid.

•   Schottky defect : It is a vacancy defect in ionic solids. decreases the density of substance.

•   Vacancy defect : When some of the lattice sites are vacant, the crystal is said to have vacancy defect. This results in decrease in density of the substance.

•   Interstitial defect :When some constituent particles occupy an interstitial site, the crystal is said to have interstitial defect. This defect increases the density of the substance.