An odorless,colorless,flammable gas,CH4,the major constituent of natural gas,that is used as a fuel and is an important source of hydrogen and a wide variety of organic compounds.

• 甲烷一种无味，无色，易燃汽体，CH4，是天然气的主要组成部分，被用作燃料，是氢和其它多种有机化合物的重要来源