The repeat unit of a polymer is the smallest section of the polymer that includes all of the original monomers and is identically repeated end to end along the entire polymer chain.

Draw the repeat unit of the polymer that results via a condensation reaction , as shown in Intro figure 2, between the diacid and the diamine shown below.

To indicate that the polymer repeats, leave the atom at each end of the repeat unit with one less bond. For example, leave a carbon atom with three bonds or a nitrogen atom with two bonds.

HO Terephthalic Acid OH HN NH 1,1-Diaminoethane