Assertion: p-type semiconductors are good conductors of electricity due to metal excees defects
Reason: f-centres are created due to metal excess defects

Options

A. If both assertion and reason are correct and reason is correct explanation for assertion
B. If both assertion and reason are correct but reason is not correct explanation for assertion
C. If assertion is correct but reason is incorrect
D. If both assertion and reason are incorrect

Explanation

To analyze the given question, we will break it down into its components: the assertion and the reason, and evaluate their correctness.

### Step 1: Evaluate the Assertion
**Assertion**: "p-type semiconductors are good conductors of electricity due to metal excess defects."

- **Explanation**: P-type semiconductors are formed when a group 14 element (like silicon or germanium) is doped with a trivalent impurity (such as boron or gallium). This doping creates "holes" in the crystal lattice, which are positively charged carriers. The conductivity in p-type semiconductors is primarily due to these holes, not due to metal excess defects. Therefore, the assertion is **incorrect**.

### Step 2: Evaluate the Reason
**Reason**: "f-centres are created due to metal excess defects."

- **Explanation**: F-centres are defects in ionic crystals that arise from anion vacancies. When anions (like Cl⁻ in NaCl) are missing from their lattice sites, electrons occupy these vacancies, creating F-centres. This process is not related to metal excess defects but rather to anion vacancies. Thus, the reason is also **incorrect**.

### Step 3: Conclusion
Since both the assertion and the reason are incorrect, we can conclude that the correct answer is that both statements are false.

### Final Answer
Both the assertion and the reason are incorrect.

---