In a crystal, Frenkel defect is not shown by alkali metal halides but silver halides show. Why ?

In a crystal, Frenkel defect is not shown by alkali metal halides but

1.	In a crystal, Frenkel defect is not shown by alkali metal halides but silver halides show. Why ?
Answer» Solution :Frenkel DEFECT is found in silver HALIDES due to SMALL size of `Ag^+` ION which can enter into interstitial site. It is not found in alkali metal halides, as the alkali metal ions are too big to fit into the interstitial SITES.