Evaluating Halogen Statements for Accuracy

Steps:

• Statement 1 is correct: Halogens (F, Cl, Br, I, At) are non-metals forming diatomic molecules (X₂) in their standard states.
• Statement 2 is correct: Chlorine, being more reactive, displaces Br⁻ and I⁻ via redox reactions, e.g., Cl₂ + 2Br⁻ → Br₂ + 2Cl⁻.
• Statement 3 is incorrect: Halogen reactivity decreases down Group 7 as atomic size increases, weakening electron affinity (F most reactive, I least).
• Therefore, only statements 1 and 2 hold true.

Why B is correct:

• B identifies 1 and 2 only, aligning with halogen reactivity trends defined by decreasing oxidizing power down the group.

Why the others are wrong:

• A includes incorrect statement 3 on reactivity.
• C omits correct statement 2 on displacement.
• D omits correct statement 1 on molecular nature.

Final answer: B