Which of the following statement(s) is/are correct? 

Options

A. Frenkel defects occur when difference in size of cations and anions are bigger
B. Schottky defects occur when cations and anions have similar ionic size
C. An ionic crystal can have both Frenkel and Schottky defects
D. Pure alkali metals do not have Frenkel defects

Answer

A, B, C, D

Explanation

Shottkey defect occur when cation & anion are similer in size but the size of cation & anion are different in Frenkel defect. Generaly ionic crystals have both schottkey frenkel defects. Pure alkali metals do not Frenkel defect.