Methane is the simplest alkane hydrocarbon, whose chemical formula is CH4. Each of the hydrogen atoms is bonded to carbon by a covalent bond. It is a non-polar substance that occurs as a gas at ordinary temperatures and pressures. It is colorless, odorless and insoluble in water.
Ethane is an aliphatic alkane hydrocarbon with two carbon atoms, formula C2H6. Under normal conditions it is gaseous and an excellent fuel. Its boiling point is -88 °C. It is found in appreciable quantities in natural gas.
Propane is a colorless, odorless gas. It belongs to the aliphatic hydrocarbons with carbon single bonds, known as alkanes. Its chemical formula is C3H8.
Butane, also called n-butane, is a saturated, paraffinic or aliphatic, flammable, gaseous hydrocarbon that liquefies at atmospheric pressure at -0.5 °C, consisting of four carbon atoms and ten hydrogen atoms, whose chemical formula is C4H10. An isomer of this gas can also be called by the same name: isobutane or methylpropane.