term polymer stems from the Greek roots poly (many) and meros (part). The word thus
means “many parts” and designates a molecule made up by the repetition of some simpler unit
called a mer. Polymers contain thousands to millions of atoms in a molecule that is large; they
are also called macromolecules. Polymers are prepared by joining a large number of small
molecules called monomers.
The structure of polystyrene, for example, can be w
or, more conveniently, as (II), which depicts the mer or repeating unit of the molecule within
parentheses with a subscript, such as n, to represent the number of repeating u
