Statement 1: Frenkel defect showa interstitial as well as vacancy effect
Statement 2: In Frenkel defect, solids show color because of F-centre.

Options

A. Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of statement 1.
B. Statement 1 is true, Statement 2 is false
C. Statement 1 is flase, Statement 2 is true
D. Statement 1 is false, Statement 2 is false

Answer

To solve the question, we need to analyze both statements regarding the Frenkel defect in solids.

### Step 1: Understanding Frenkel Defect
A Frenkel defect occurs when an ion leaves its normal lattice position and occupies an interstitial site. This creates a vacancy at the original site and an interstitial defect where the ion is now located.

### Step 2: Analyzing Statement 1
**Statement 1:** "Frenkel defect shows interstitial as well as vacancy effect."
- In a Frenkel defect, ions (usually cations) move from their lattice positions to interstitial sites, creating vacancies in the lattice. Therefore, this statement is **true**.

### Step 3: Analyzing Statement 2
**Statement 2:** "In Frenkel defect, solids show color because of F-centre."
- F-centres are associated with anion vacancies and are typically found in non-stoichiometric defects, not in Frenkel defects. F-centres result from the presence of excess cations that occupy vacancies left by anions, leading to color in the solid. Since Frenkel defects do not directly lead to F-centres, this statement is **false**.

### Conclusion
- Statement 1 is true.
- Statement 2 is false.

Thus, the correct answer is that Statement 1 is true and Statement 2 is false.

### Final Answer
- Statement 1: True
- Statement 2: False