According to V.B.T., atoms of element form bond only to pair up their unpaired electrons present in β Chemical Bonding Chemistry Question
Question
According to V.B.T., atoms of element form bond only to pair up their unpaired electrons present in ground state or excited state. This pairing of unpaired electron will take place by overlapping of orbitals each one having one unpaired electron with opposite spin.

π‘ Solution & Explanation
Step 1: Identify that ortho-fluorophenol (I) exhibits strong intramolecular hydrogen bonding, which significantly decreases its capacity to form intermolecular hydrogen bonds, thereby lowering its boiling point. Step 2: For ortho-chlorophenol (II) and ortho-bromophenol (III), intramolecular hydrogen bonding is weak or negligible due to the larger size of Cl and Br. Therefore, their boiling points are primarily governed by van der Waals forces, which increase with molecular size and weight (III > II). Step 3: Consequently, the boiling point order is III > II > I, which matches option (b).