KBr shows which of the following defects ?

Options

A. Frenkel defect
B. Schottky defect
C. Metal excess defect
D. Metal deficiency

Answer

To determine the type of defects shown by KBr (Potassium Bromide), we need to analyze its ionic structure and the characteristics of its cations and anions.

### Step-by-Step Solution:

1. **Identify the Ions in KBr**:
- KBr is composed of potassium ions (K⁺) and bromide ions (Br⁻).
- Potassium is a cation, and bromide is an anion.

2. **Compare the Sizes of Ions**:
- The ionic sizes of K⁺ and Br⁻ are comparable. This means that the size difference between the cation and anion is minimal.
- This similarity in size is crucial for understanding the types of defects that can occur in the crystal lattice.

3. **Understand Types of Defects**:
- In ionic solids, defects can occur due to the absence of ions in their lattice positions.
- The main types of defects include:
- Schottky defects
- Frenkel defects
- Interstitial defects

4. **Identify the Defect in KBr**:
- Given that K⁺ and Br⁻ ions have similar sizes, KBr is likely to exhibit Schottky defects.
- Schottky defects occur when both cations and anions leave their lattice sites, creating vacancies. This results in a decrease in the density of the solid.

5. **Conclusion**:
- KBr shows Schottky defects, where both K⁺ and Br⁻ ions are missing from their lattice positions, leading to vacancies.

### Final Answer:
KBr shows Schottky defects.

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