Which option describes an alkene?

Which option describes an alkene?

• A. C=C (double bond)
• B. carbon-carbon triple bond
• C. C-O-C
• D. C=O

Answer: (A)

An alkene is a hydrocarbon that has a carbon–carbon double bond. That double bond is written as C=C, and it’s the defining feature of alkenes. The presence of a C=C bond makes these molecules unsaturated and gives them characteristic reactivity and geometry (such as cis/trans isomerism in substituted cases). The option showing a carbon–carbon double bond matches this definition. A carbon–carbon triple bond would describe an alkyne, not an alkene. C-O-C represents an ether linkage, and C=O is a carbonyl group found in aldehydes and ketones, not alkenes.

An alkene is a hydrocarbon that has a carbon–carbon double bond. That double bond is written as C=C, and it’s the defining feature of alkenes. The presence of a C=C bond makes these molecules unsaturated and gives them characteristic reactivity and geometry (such as cis/trans isomerism in substituted cases).

The option showing a carbon–carbon double bond matches this definition. A carbon–carbon triple bond would describe an alkyne, not an alkene. C-O-C represents an ether linkage, and C=O is a carbonyl group found in aldehydes and ketones, not alkenes.