Reducing atmosphere that sodium is reduced and evaporated to produce the sodium tail of the Moon (see atmosphere of the Moon). Reducing atmosphere A reducing atmosphere is an atmospheric condition in which oxidation is prevented by removal of oxygen and other oxidizing gases or vapours, and which may contain actively reducing gases such as hydrogen, carbon monoxide, and gases such as hydrogen sulphide that would be oxidized by any present oxygen. In metal processing, a reducing atmosphere is used in annealing ovens for relaxation of metal stresses without corroding the metal. A non oxidizing gas, usually nitrogen, is used, or for more
Atmosphere of Earth takes place in the troposphere, and it is the only layer that can be accessed by propeller-driven aircraft. Within the five principal layers above, that are largely determined by temperature, several secondary layers may be distinguished by other properties: The average temperature of the atmosphere at Earth's surface is or , depending on the reference. The average atmospheric pressure at sea level is defined by the International Standard Atmosphere as . This is sometimes referred to as a unit of standard atmospheres (atm). Total atmospheric mass is 5.1480×10 kg (1.135×10 lb), about 2.5% less than would be inferred from the