Final answer:
Ethene molecules undergo addition polymerization, where the double bonds break and form single bonds with other ethene units, resulting in the formation of polyethylene, a long chain polymer.
Step-by-step explanation:
The process of forming a polymer from monomers such as ethene involves the breaking of double bonds and the formation of single bonds between the monomer units. Ethene (C2H4), which is also known as ethylene, has each carbon atom double-bonded to the other, with two hydrogen atoms bonded to each carbon. During polymerization, the double bond opens up allowing each ethene molecule to connect with other ethene molecules to form a long chain, a process known as addition polymerization. The structure of the resulting polymer, polyethylene, is represented by repeating units of the ethene molecule where the double bonds have been converted to single bonds between carbons extending the chain. Thus, the reaction can be abbreviated as follows: nCH2=CH2 → [-CH2CH2-]n.
In this polymer chain, each carbon atom has four bonds: two to hydrogen atoms and two to other carbon atoms (one to the previous carbon atom in the chain and one to the next). This new structure is the result of a chain reaction where one ethene molecule after another adds to the growing chain, creating part of a very long molecular chain that makes up the polymer.