Forming gas Forming gas Forming gas is a mixture of hydrogen (mole fraction varies) and nitrogen. It is sometimes called a "dissociated ammonia atmosphere" due to the reaction which generates it: It can also be manufactured by thermal cracking of ammonia, in an ammonia cracker or forming gas generator. Forming gas is used as an atmosphere for processes that need the properties of hydrogen gas. Typical forming gas formulations (5% H2 in N2) are not explosive. It is used in chambers for gas hypersensitization, a process in which photographic film is heated in forming gas to drive out moisture and oxygen and
Atmosphere bodies within the Solar System have extremely thin atmospheres not in equilibrium. These include the Moon (sodium gas), Mercury (sodium gas), Europa (oxygen), Io (sulfur), and Enceladus (water vapor). The first exoplanet whose atmospheric composition was determined is HD 209458b, a gas giant with a close orbit around a star in the constellation Pegasus. Its atmosphere is heated to temperatures over 1,000 K, and is steadily escaping into space. Hydrogen, oxygen, carbon and sulfur have been detected in the planet's inflated atmosphere. Earth's atmosphere consists of a number of layers that differ in properties such as composition, temperature and pressure.