| − | '''Methane''' ('''CH<sub>4</sub>''') is a [[chemical]] substance found in a high percentage in [[natural gas]]. It is also a common byproduct of [[digestion]] in humans and [[animal]]s. It is also known as "marsh gas" or "swamp gas" because it is produced when vegetation decomposes in water. Methane is lighter than air and is extremely volatile. It tends to dissipate quickly, but a large enough concentration can displace breathable air. | + | '''Methane''' ('''CH<sub>4</sub>''') is a [[chemical]] substance found in a high percentage in [[natural gas]]. It is also a common byproduct of [[digestion]] in humans and [[animal]]s. It is also known as "marsh gas" or "swamp gas" because it is produced when vegetation decomposes in water. Methane is lighter than air and is extremely volatile. It tends to dissipate quickly, but a large enough concentration can displace breathable air. Methane is an important constituent of [[natural gas]]. |