Which of the following statements about the chemical properties of alkanes is true?

Alkanes are a class of hydrocarbons characterized by single carbon-to-carbon bonds and a general formula of CnH2n+2. Their chemical properties are largely defined by their saturated nature and the strength of the C-H and C-C bonds. Alkanes are known for being relatively unreactive compared to other organic compounds, primarily due to the strong sigma bonds that exist within their structure.

The statement that alkanes are mostly unreactive is accurate because they typically do not react readily with many reagents. For example, they do not participate in addition reactions that are common with alkenes and alkynes, owing to the lack of double or triple bonds. Instead, alkanes mainly undergo combustion and substitution reactions when reacted with halogens, but these reactions require specific conditions, such as the presence of heat or light.

This characteristic of alkanes contributes to their stability, making them suitable for use as fuels and in various industrial applications where reactivity is not desired. Thus, the correct choice reflects the inherent stability and lower reactivity of alkanes in comparison to other organic compounds, making them mostly unreactive in a wider range of chemical contexts.