Step 1: Understand what a functional group is. A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule.
Step 2: Identify what alkenes are. Alkenes are a type of hydrocarbon that contains at least one carbon-carbon double bond.
Step 3: Recognize the specific feature of alkenes. The key feature of alkenes is the presence of a double bond between two carbon atoms.
Step 4: Conclude that the functional group in alkenes is the carbon-carbon double bond, which is often represented as C=C.
