Which polymerization occurs when the electrons in double or triple bonds in the monomer units are rearranged?

Which polymerization occurs when the electrons in double or triple bonds in the monomer units are rearranged?

• A. Addition polymerization
• B. Condensation polymerization
• C. Fractional distillation
• D. Reforming

Answer: (A)

The key idea is addition polymerization, where monomers that have carbon–carbon double bonds join together by opening those pi bonds and linking end to end. As the chain grows, the electrons from the double bond are rearranged to form a new C–C bond with the growing chain, turning the double bond into a single bond in the backbone. No small molecule is released in this process, so each added unit simply adds onto the chain in sequence. This fits the description because the defining feature is that the electrons in the double bonds are re-routed to form the extended polymer, rather than forming a byproduct or requiring a reaction between two different functional groups. By contrast, condensation polymerization involves forming bonds with the loss of a small molecule (like water), and the other two options aren’t polymerization mechanisms.

The key idea is addition polymerization, where monomers that have carbon–carbon double bonds join together by opening those pi bonds and linking end to end. As the chain grows, the electrons from the double bond are rearranged to form a new C–C bond with the growing chain, turning the double bond into a single bond in the backbone. No small molecule is released in this process, so each added unit simply adds onto the chain in sequence.

This fits the description because the defining feature is that the electrons in the double bonds are re-routed to form the extended polymer, rather than forming a byproduct or requiring a reaction between two different functional groups. By contrast, condensation polymerization involves forming bonds with the loss of a small molecule (like water), and the other two options aren’t polymerization mechanisms.