Final answer:
Nonene is an alkene because alkenes are characterized by at least one carbon-carbon double bond, and nonene has nine carbon atoms with at least one double bond.
Step-by-step explanation:
The question asks to identify which compound among the given options is an alkene. Alkenes are hydrocarbons with at least one carbon-carbon double bond. Based on the definitions and nomenclature of organic chemistry:
- Butyne is an alkyne, which means it has a carbon-carbon triple bond.
- Nonene refers to an alkene with nine carbon atoms and at least one double bond.
- Methane is an alkane with a single carbon atom and no double bonds.
- Propanone is a ketone, not an alkene.
Therefore, the compound that is an alkene from the choices provided is b) Nonene.