Answer: The reaction between them is called as halogenation of alkene.
Step-by-step explanation:
Ethene is a hydrocarbon in which double bond is present between carbon-carbon atoms.
When chlorine gas is reacted with ethene molecule, it results in the addition of chlorine molecule to the double bond.
This reaction is known as halogenation reaction.
The chemical equation for this reaction follows:
Hence, the reaction between them is called as halogenation of alkene.