What are the simplest examples of alkanes?

The simplest examples of alkanes are methane (${\text{CH}}_4$), ethane (${\text{C}}_2{\text{H}}_6$), propane (${\text{C}}_3{\text{H}}_8$), and butane (${\text{C}}_4{\text{H}}_{10}$).12

These compounds are hydrocarbons consisting entirely of carbon and hydrogen atoms joined by single covalent bonds. Methane, ethane, and propane are the only alkanes uniquely defined by their molecular formulas. Starting with butane, however, the existence of isomers—compounds with the same molecular formula but different atomic arrangements—becomes possible; for instance, ${\text{C}}_4{\text{H}}_{10}$ exists as both n-butane and isobutane.12