Which of the following is incorrect with respect to property indicated ? 

Options

A. `E.N : F gt Cl gt Br`
B. `E.A : Cl gt Br lt F`
C. Oxidising power : `F_2 gt Cl_2 gt Br_2`
D. Bond energy : `F_2 gt Cl_2 gt Br_2`

Answer

To solve the question regarding which property indicated is incorrect, we will analyze the provided options step by step:

### Step 1: Analyze Electronegativity
- **Statement**: Electronegativity order: Fluorine > Chlorine > Bromine.
- **Explanation**: Electronegativity indeed decreases down the group in the periodic table. Fluorine is the most electronegative element, followed by chlorine and then bromine. Therefore, this statement is **correct**.

### Step 2: Analyze Electron Affinity
- **Statement**: Electron affinity order: Chlorine > Bromine > Fluorine.
- **Explanation**: The electron affinity of fluorine is less than that of chlorine due to the small size of the fluorine atom, which causes strong inter-electronic repulsion in the 2p orbital. Thus, the incoming electron does not experience much attraction. Therefore, this statement is also **correct**.

### Step 3: Analyze Oxidizing Power
- **Statement**: Oxidizing power order: Fluorine > Chlorine.
- **Explanation**: Fluorine is indeed a stronger oxidizing agent than chlorine due to its low bond dissociation energy and high hydration energy. Thus, this statement is **correct**.

### Step 4: Analyze Bond Energy
- **Statement**: Bond energy order: F2 < Cl2 < Br2.
- **Explanation**: The bond dissociation energy of F2 is actually lower than that of Cl2, making this statement incorrect. The bond energy of F2 is weaker than Cl2 due to the repulsion between the lone pairs in the F2 molecule. Therefore, this statement is **incorrect**.

### Conclusion
- The incorrect statement is regarding bond energy: F2 < Cl2 < Br2.

### Final Answer
The incorrect property indicated is the bond energy order: F2 < Cl2 < Br2 (Option D).

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