Question

Which of the following crystals does not exhibit Frenkel defect?

• A. $AgBr$
• B. $AgCl$
• C. $KBr$
• D. $ZnS$

Answer 1

The correct option is C $KBr$

Condition for Frankel defects in an ionic crystal is-

1. The size difference between the ions should be large.
   
2. Smaller ion (cation) move to interstitial site.

Frenkel defect generally appears in ZnS, AgBr, AgI, AgCl etc.

Alkali metal shows Schottky defect. Here KBr exhibits Schottky defect. However, it does not show Frankel defect. ZnS has a large size difference between the ions.
Option C is correct.