Alkanes have $sp^3$-hybridized carbons that dispose their four substituents toward the corners of a tetrahedron.

The simplest alkane is methane, formed by a single carbon that bonds with four hydrogens. Bond angles in methane are 109.5° and carbon-hydrogen bond distances are 108.70 pm. Alkanes have the molecular formula $C_nH_{2n+2}$, where n represents the number of carbons in the molecule.