Some compounds are molecules like CO2 and some are polymers. What are polymers

Polymers are the molecular structure in which the larger number of  small units are bond together.

Explanation:

The polymer are composed of hydrocarbon the components of carbon and hydrogen. The polymers are resistant to chemiclas, they act as both thermal and electrical insulators, they can be processed in various ways usually made up of petroleum. polymers are used to make items that have no alternatives from other material.

They have covalent bonds that holds the atoms in the polymer molecules together and secondary bonds that holds group of polymer chains together to form the polymeric material.

Diamond and graphite are polymers.

Carbon dioxide is a molecule with molecular formula CO2 and it is made up of two oxygen atoms and covalently bonded with one carbon atom.