What is the main characteristic of hydrocarbons classified as alkanes?

Hydrocarbons classified as alkanes are characterized by having only single bonds between carbon atoms. This means that each carbon atom is connected to its neighboring carbon atoms through a single covalent bond, which results in a saturated hydrocarbon. The general formula for alkanes is CnH2n+2, indicating that for every n carbon atoms, there are twice that number plus two hydrogen atoms, reflecting the complete saturation of hydrogen atoms around the carbon framework.

In contrast, hydrocarbons that contain double bonds (like alkenes) or triple bonds (like alkynes) are unsaturated, which provides differing chemical properties and reactivity. Similarly, the presence of rings indicates a cyclic structure, which can also define different classes of hydrocarbons, including cycloalkanes. However, for alkanes specifically, the defining feature is their lack of double or triple bonds and the exclusive presence of single bonds.