Question

Schottky defect in crystals is observed when:
[1 Mark]

• A. Density of the crystal is increased
• B. Unequal number of cations and anions are missing from the lattice
• C. An ion leaves its normal site and occupies an interstitial site
• D. Equal number of cations and anions are missing from the lattice

Answer 1

The correct option is D Equal number of cations and anions are missing from the lattice

In Schottky defect, equal no. of cations and anions are missing from the lattice. So, the crystal remains neutral. Such defect is more common in highly ionic compounds of similar cationic and anionic size, i.e. $NaCl$.