A : Atomic size of F is smaller than that of Cl .
R : F- F bond is stronger than Cl-Cl bond .

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion , then mark (2)
C. If Assertion is true statement but Reason is false , then mark (3)
D. If both Assertion and Reason are false statements , then mark (4)

Answer

To solve the question, we need to analyze the two statements:

**Assertion (A)**: The atomic size of F is smaller than that of Cl.
**Reason (R)**: F-F bond is stronger than Cl-Cl bond.

### Step 1: Analyze the Assertion
- The atomic size of elements in the same group increases as we move down the group in the periodic table. This is because additional electron shells are added, which increases the distance between the nucleus and the outermost electrons.
- Fluorine (F) is located above chlorine (Cl) in Group 17 (the halogens). Therefore, fluorine has a smaller atomic size compared to chlorine.

**Conclusion**: The assertion is **true**.

### Step 2: Analyze the Reason
- The strength of a bond can be influenced by several factors, including atomic size and electron-electron repulsion.
- The F-F bond is indeed weaker than the Cl-Cl bond. This is primarily due to the small size of fluorine, which leads to significant electron-electron repulsion between the non-bonding pairs of electrons in the F2 molecule. In contrast, chlorine has larger atomic size and fewer repulsive interactions, making the Cl-Cl bond stronger.

**Conclusion**: The reason is **false**.

### Step 3: Determine the Correct Option
- Since the assertion is true and the reason is false, the correct option is that the assertion is true but the reason is false.

**Final Answer**: The correct option is **Option 3**: Assertion is true but reason is false.

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