Which type of hydrocarbon is more reactive?

The reactivity of hydrocarbons is significantly influenced by their structure and the types of bonds present within the molecules. Alkenes, which are indicated as the correct answer, contain at least one carbon-carbon double bond (C=C). This double bond is a point of high electron density, making alkenes more reactive compared to alkanes (which only have single bonds) and cycloalkanes (which are similar to alkanes in terms of bonding).

The presence of the double bond in alkenes allows them to undergo addition reactions, where other atoms or groups can be added to the carbon atoms involved in the double bond. This contrasts with alkanes and cycloalkanes, which primarily participate in substitution reactions and are generally less reactive due to the stability of their single bonds.

Aromatic hydrocarbons are also less reactive compared to alkenes because of their stable ring structure and delocalized electrons, which provide a certain level of stability that reduces their reactivity in comparison to alkenes.

Overall, the structural features of alkenes contribute to their higher reactivity, making them an important class of hydrocarbons for various chemical reactions, especially in organic chemistry.