Which of the following has Frenkel defect?

Options

A. Sodium chloride
B. Graphite
C. Silver bromide
D. Diamond

Explanation

To determine which of the given compounds has a Frenkel defect, we need to understand what a Frenkel defect is and the conditions under which it occurs.

### Step-by-Step Solution:

1. **Understand the Frenkel Defect**:
- A Frenkel defect occurs in ionic solids where there is a vacancy created by an ion leaving its lattice site and occupying an interstitial site. This defect typically occurs when there is a significant size difference between cations and anions.

2. **Identify Characteristics**:
- For a Frenkel defect to occur, the following conditions must be met:
- There should be a large size difference between cations and anions.
- The compound must be ionic in nature.
- The defect must maintain electrical neutrality.

3. **Analyze Given Options**:
- The question provides several compounds. We need to analyze each one to see if they can exhibit a Frenkel defect:
- **Option A: AgCl (Silver Chloride)** - This compound has a significant size difference between Ag⁺ and Cl⁻ ions, making it a candidate for Frenkel defect.
- **Option B: NaCl (Sodium Chloride)** - Na⁺ and Cl⁻ ions are of similar size, so it does not exhibit a Frenkel defect.
- **Option C: Graphite** - Graphite is a covalent network solid and does not have cations and anions; hence, it cannot exhibit a Frenkel defect.
- **Option D: AgBr (Silver Bromide)** - Similar to AgCl, AgBr has a significant size difference between Ag⁺ and Br⁻ ions, making it another candidate for Frenkel defect.

4. **Conclusion**:
- Based on the analysis, both AgCl and AgBr can exhibit Frenkel defects due to the large size difference between their respective cations and anions. However, since the question asks for one example, the most commonly referenced examples of Frenkel defects are AgCl and AgBr.

5. **Final Answer**:
- The correct answer is **AgBr (Silver Bromide)**, as it is explicitly mentioned in the analysis and is a classic example of a compound that exhibits a Frenkel defect.