Which term describes a polymer formed by linking many of the same monomers?

• A. Addition polymer
• B. Condensation polymer
• C. Polymer chain
• D. Biopolymer

Answer: (A)

Joining many identical monomers to make a long polymer is called addition polymerization. The product, an addition polymer, forms when each monomer adds to the growing chain without losing any small molecule, so the polymer contains all the monomer units in a row. This explains why the term fits the description in the question. For example, polyethylene is made from many ethene units linked together. Condensation polymers form with the loss of a small molecule like water, so they’re not simply defined by adding identical monomers. A polymer chain is just the long molecule itself, and a biopolymer is a natural polymer such as proteins or DNA, regardless of how it was formed.