Assessment and Qualifications Alliance (AQA) GCSE Chemistry Paper 2 Practice Exam

In an addition polymerization reaction, monomers, which are small, reactive molecules, chemically bond together to form larger, long-chain molecules known as polymers. This process involves the opening of double bonds in the monomers, allowing them to link together in a repeating pattern without the loss of any atoms or small molecules. The result is a significant increase in molecular mass and complexity, producing materials that can exhibit different physical and chemical properties compared to the original monomers. The formation of these larger molecules is fundamental to the production of many common plastics and synthetic fibers.

In contrast, the other options do not accurately represent what occurs during this specific type of reaction. For instance, breaking apart into smaller molecules refers to a process like depolymerization, while combustion involves chemical reactions with oxygen leading to the release of energy, and the formation of salts pertains to the combination of acids and bases, neither of which relates to the process of addition polymerization.