Correct Answer – 1
Frankel defect is shown by ionic solid in which there is a large different in the size of ions (and hence the coordination number is low).for example `ZnS,AgCl,AgBr` and `Agl` due to small size of `Zn^(2+)` and `Ag^(+)` ions.
In defect the smaller ion (usually cation) is dislocated from its normal site to an interstitial site.This creates a vacancy defect at its origin site and are interstitial defect at its new location.Therfore Frenkel defect is also called dislocation defect. it does not change the density of the solid.