Butane (C4H10) is a saturated hydrocarbon with four carbon atoms and ten hydrogen atoms. It exists as two structural isomers: n-butane, with a linear carbon chain, and isobutane, with a branched structure. Both isomers are colorless, flammable gases at room temperature. Butane has a boiling point of -0.5°C (n-butane) and -11.7°C (isobutane), and it is commonly used as a fuel and in the production of synthetic rubber.