Interhalogen Compounds

Interhalogen compounds form between two different halogens and tend to be more reactive than the parent halogens because the bond between two unlike halogen atoms is weaker than the bond in the pure halogen molecules. The difference in size and electronegativity between the two atoms makes the interhalogen bond longer, weaker, and more polar, so it breaks easily and reacts readily, often acting as a strong halogenating and oxidising agent. The option of stronger halogen-halogen bonds is the opposite of the truth. The option that they are ionic solids is incorrect, since most interhalogens are covalent and often liquids or gases. The option that they contain no halogen atoms is absurd, since they are made entirely of halogens. The reactivity and structures of interhalogens are a standard NCERT topic for Group 17. Working through the logic step by step, rather than memorising the result, makes it clear why weak bond governs the behaviour seen here. Examiners frequently test whether a student can connect bond polarity with the underlying principle rather than merely recalling an isolated fact. Plausibility check: the weaker, more polar bond in a mixed-halogen molecule readily dissociates to give reactive halogen species, confirming the enhanced reactivity.