Answer: Cis configuration.
- A Trans configuration
- B Alternating cis and trans units
- C Cis configuration
- D Fully aromatic backbone
Correct answer: C. Cis configuration
Explanation: Natural rubber is cis-1,4-polyisoprene; the cis double bonds prevent the chains from packing closely, giving coiled, elastic chains. Gutta-percha is the trans isomer.
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.