Ethene on polymerization gives the product polyethylene. This reaction may be called as:

Explanation

Polymerization of ethene involves the addition of many ethene molecules to form a long-chain hydrocarbon called polyethylene. During the polymerization process, the carbon-carbon double bond in ethene is broken, and the carbons in the double bond form single bonds with other ethene molecules. As a result, the polymer chain grows longer and longer with each addition, ultimately forming a long-chain polymer. This reaction is called an addition polymerization reaction because the monomers add together to form the polymer.Condensation reactions, on the other hand, typically involve the elimination of a small molecule, such as water or alcohol, as the monomers react to form a polymer. Substitution and pyrolysis reactions are different types of reactions that do not apply to the polymerization of ethene to form polyethylene.