Question

Schottky defect in crystals is observed when

• A. unequal number of cations and anions are missing from the lattice
• B. equal number of cations and anions are missing from the lattice
• C. an ion leaves its normal site and occupies an interstitial site
• D. density of the crystal is increased

Hint:

In Schottky defects, both cations and anions are missing, leading to vacancies but no net charge imbalance.

Answer 1

The Correct Option is B

Step 1: Understand Schottky defect.
Schottky defects occur when equal numbers of cations and anions are missing from the lattice, resulting in vacancies that maintain the electrical neutrality of the crystal.
Step 2: Conclusion.
Thus, Schottky defects are characterized by an equal number of cations and anions being absent from their normal lattice sites.
Final Answer: \[ \boxed{\text{equal number of cations and anions are missing from the lattice}} \]