Most of the oxygen produced is used in steelmaking, where it oxidizes impurities in molten iron, and hastens the conversion of the iron to steel. It is also used to create artificial atmospheres in submarines and hospital oxygen tents, and is vital in this capacity for astronauts and divers. Liquid oxygen is used as a propellant in spacecraft.
Most sulphur is used to make sulphuric acid, which has a vast array of applications. Products derived from the acid include detergents, drugs, dyes, paints and plastics. Sulphur is also used in the vulcanization process for hardening rubber.
Selenium's photoconductive properties make the element of use in photoelectric cells. Selenium sulphide is used in the treatment of skin diseases, and sodium selenide imparts a red colour to glasses and ceramics.
Tellurium too is used in glassmaking, its oxide being used to tint glass blue. And like sulphur, tellurium is used in the vulcanization of rubber. The element's chief use, however, is in the production of steel and non-ferrous alloys.
Polonium, a radioactive element, is used as a source of power in space satellites.
