Assertion (A): LiF is ionic in nature.
Reason (R): Lil is covalent in nature.

Options

A. Both A and Rare true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but Ris true

Explanation

To analyze the assertion and reason provided in the question, we will follow a systematic approach.

### Step 1: Understand the Assertion
The assertion states that "LiF is ionic in nature."
- To determine if LiF is ionic, we need to consider the electronegativity difference between lithium (Li) and fluorine (F).

### Step 2: Calculate the Electronegativity Difference for LiF
- The electronegativity of lithium (Li) is approximately 1.0, and that of fluorine (F) is approximately 4.0.
- The electronegativity difference (ΔEN) can be calculated as:
\[ ΔEN = EN(F) - EN(Li) = 4.0 - 1.0 = 3.0 \]

### Step 3: Determine the Nature of LiF
- According to the general rule, if ΔEN ≥ 1.7, the bond is considered ionic.
- Since 3.0 is greater than 1.7, we conclude that LiF is indeed ionic in nature.

### Step 4: Understand the Reason
The reason states that "LiI is covalent in nature."
- We need to calculate the electronegativity difference for lithium iodide (LiI).

### Step 5: Calculate the Electronegativity Difference for LiI
- The electronegativity of iodine (I) is approximately 2.5.
- The electronegativity difference (ΔEN) for LiI can be calculated as:
\[ ΔEN = EN(I) - EN(Li) = 2.5 - 1.0 = 1.5 \]

### Step 6: Determine the Nature of LiI
- Since ΔEN = 1.5, which is less than 1.7, we conclude that LiI is covalent in nature.

### Step 7: Conclusion
- Both the assertion and reason are true:
- Assertion (A): LiF is ionic in nature. (True)
- Reason (R): LiI is covalent in nature. (True)
- However, the reason provided does not correctly explain the assertion, as the ionic nature of LiF does not depend on the covalent nature of LiI.

### Final Answer
The assertion is true, the reason is true, but the reason is not the correct explanation of the assertion. Therefore, the correct option is that both are true, but the reason does not explain the assertion.

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