Methane (CH4) is a clean-burning fuel that is the main constituent of natural gas, the type of gas piped into homes. The combustion of methane (CH4) is similar to that of hydrogen, though with methane, many more chemical reactions take place before stable molecules form.
When ignited, a molecule of methane reacts with two molecules of oxygen (O2). The end result is three new molecules: two molecules of water (H2O) and one of carbon dioxide (CO2).