The weakest intermolecular forces are present in
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Neoprene
Polymers are classified by the strength of the forces between their chains:
Elastomers (rubbers): the chains are held by the weakest intermolecular forces, so they can be stretched and spring back; e.g. buna-S, buna-N, neoprene.
Thermoplastics: intermediate forces; e.g. polythene, polystyrene, PVC.
Fibres: strong forces such as hydrogen bonding; e.g. nylon 6,6, terylene.
Why the other options are incorrect
Option (2) Nylon 6, 6 — Incorrect. A fibre; its chains are held by strong hydrogen bonds.
Option (3) Polyvinyl chloride — Incorrect. A thermoplastic, with intermediate forces.
Option (4) Polystyrene — Incorrect. Also a thermoplastic.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.