What is the key difference between alkanes and alkenes?

The key difference between alkanes and alkenes lies in their bonding and saturation levels. Alkenes are characterized by the presence of at least one carbon-carbon double bond (C=C) within their structure. This double bond results in a degree of unsaturation, which differentiates alkenes from alkanes, the latter of which consist only of single carbon-carbon bonds (C-C) and are thus classified as saturated hydrocarbons.

The presence of this double bond in alkenes allows them to engage in additional types of chemical reactions, such as additions, that alkanes cannot. This fundamental distinction is crucial for understanding their chemical behavior, reactivity, and properties. In contrast, alkanes are more stable and less reactive due to their saturated nature, making the identification of this double bond in alkenes the defining factor that separates them from alkanes.