Answer: Weak forces and few cross-links.
- A Strong hydrogen bonds
- B Rigid covalent networks
- C Weak forces and few cross-links
- D Strong dipole-dipole forces
Correct answer: C. Weak forces and few cross-links
Explanation: In elastomers the chains are held by the weakest intermolecular forces, with only a few cross-links, so the coiled chains can stretch and then spring back.
Addition polymerisation simply links monomers containing a double bond with nothing left over, while condensation polymerisation joins two different monomers through a reaction (often forming an ester or amide bond) that releases a small molecule like water at each step.
Concept context
Large molecules made of repeating monomer units. Covers addition and condensation polymerisation, natural and synthetic polymers (nylon, PVC, Bakelite, natural rubber), and their real-world industrial applications.