Assertion : NaCl is more ionic than NaI.
Reason : Chlorine is more electronegative than iodine.

Options

A. If assertion is true but the reason is false
B. If assertion is false but reason is true
C. If both assertion and reason are true and the reason is the correct explanation of assertion
D. If both assertion and reason are true and the reason is not the correct explanation of assertion

Answer

To analyze the given assertion and reason, let's break it down step by step.

### Step 1: Understand the Assertion
The assertion states that NaCl is more ionic than NaI. This means that the bond in NaCl has a greater ionic character compared to the bond in NaI.

**Hint:** Consider what factors contribute to the ionic character of a bond.

### Step 2: Evaluate the Reason
The reason provided is that chlorine is more electronegative than iodine. Electronegativity is a measure of an atom's ability to attract and hold onto electrons.

**Hint:** Recall the trend of electronegativity in the periodic table as you move down a group.

### Step 3: Compare Electronegativity
Chlorine (Cl) is indeed more electronegative than iodine (I). As you move down the group in the periodic table, electronegativity decreases. Therefore, the difference in electronegativity between sodium (Na) and chlorine is greater than that between sodium and iodine.

**Hint:** Think about how the difference in electronegativity affects the ionic character of a bond.

### Step 4: Apply Fajan's Rules
According to Fajan's rules, smaller anions lead to greater ionic character. Chlorine is a smaller anion compared to iodine. This means that NaCl, which contains the smaller chloride ion, will have a more ionic character than NaI, which contains the larger iodide ion.

**Hint:** Consider the size of the ions involved in the bonds.

### Step 5: Conclusion
Both the assertion and the reason are correct:
- Assertion: NaCl is more ionic than NaI (True).
- Reason: Chlorine is more electronegative than iodine (True).

However, the reason does not fully explain the assertion. The assertion can be better explained by Fajan's rule regarding the size of the anions.

**Final Answer:** Both the assertion and reason are true, but the reason is not the correct explanation of the assertion.