What is the process of polymerization?

Polymerization is the chemical process in which small molecules called monomers react together to form larger, more complex structures known as polymers. This process involves the joining of multiple monomer units, typically through covalent bonding, leading to the creation of long chains or networks of repeating units.

In this context, the formation of polymer chains occurs through various mechanisms, such as addition polymerization or condensation polymerization, depending on the type of monomers and the conditions of the reaction. The key characteristic of polymerization is that it transforms simple, low-molecular-weight substances into high-molecular-weight compounds, which have distinct physical and chemical properties compared to their monomer counterparts.

Understanding this process is crucial in fields such as materials science and organic chemistry, where polymers play a vital role in everyday materials like plastics, rubbers, and fibers. The other choices do not accurately describe polymerization; they focus on different chemical processes, such as decomposition (breaking down polymers), ion formation (electron transfer), or reactions between different states of matter, none of which pertain to the direct formation of polymer chains from monomers.