Answer
Defination: Hydrocarbons containing one or more C=C double bonds.
Example: Propene $C_3H_6$
Work Step by Step
An alkene is an unsaturated hydrocarbon that contains at least one double bond between two carbons. The general formula is $C_nH_{2n}$. Alkenes have two fewer hydrogen atoms than the corresponding alkane.
Example: Propene $C_3H_6$