Gaseous fuel is a type of fuel that exists in a gaseous state at standard temperature and pressure. Two examples of gaseous fuels are BUTANE (6 letters) and METHANE (7 letters). BUTANE is a hydrocarbon gas composed of four carbon atoms and ten hydrogen atoms, while METHANE is a single-carbon compound composed of one carbon atom and four hydrogen atoms. Both BUTANE and METHANE are used as fuel sources in various applications, such as heating, cooking, and transportation.