Flame resulting from combustion of a gas mixture containing 77% hydrogen and 23% methane. Hydrogen is the lightest element on the periodic table. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas. Methane is important for electrical generation by burning it as a fuel in a gas turbine or steam generator. Compared to other hydrocarbon fuels, burning methane produces less carbon dioxide for each unit of heat released.