Uses of Oxygen
Oxygen is very important to all living organisms as it is needed for respiration.
Triatomic oxygen (Ozone, O3), is a very reactive allotrope of oxygen. Ozone is formed in stratosphere, the upper layer of the atmosphere. It prevents harmful ultraviolet radiations from reaching Earth's surface.
Oxygen is used along with another gas called acetylene to produce large amount of heat. It is known as the oxy-acetylene flame. The heat produced in this process is used for welding iron, steel and other metals.
One main use of oxygen is for breathing. It is carried in cylinders by mountaineers, austronauts, scuba divers etc. and also used in respirators in hospitals.
Oxygen has uses in industry. Smelting of iron ore into steel consumes 55% of commercially produced oxygen. In this process, molten iron is purified by injecting oxygen into it.