This element is no longer available.
Oxygen is of great interest because it’s the essential element in the respiratory processes of most of the living cells and in combustion processes. It’s the most abundant element in The Earth’s crust. Nearly one fifth (in volume) of the air is oxygen. Non-combined gaseous oxygen normally exists in form of diatomic molecules, O2, but it also exists in triatomic form, O3, named ozone.
In normal conditions oxygen is a colourless, odourless and insipid gas; it condensates in a light blue liquid. Oxygen is part of a small group of gasses literally paramagnetic, and it’s the most paramagnetic of all. Liquid oxygen is also slightly paramagnetic.
Oxygen is reactive and will form oxides with all other elements except helium, neon, argon and krypton. It is moderately soluble in water (30 cm3 per 1 litre of water dissolve) at 20° Celsius.
Oxygen can be separated from air by fractionated liquefaction and distillation. The main applications of oxygen in order of importance are:
- melting, refining and manufacture of steel and other metals
- manufacture of chemicals by controlled oxidation
- rocket propulsion
- medical and biological life support
- mining, production and manufacture of stone and glass products
An emergency supply of oxygen automatically becomes available for the passenger in an aircraft when the pressure drop suddenly. This oxygen is stored not as an oxygen gas but as the chemical sodium chlorate.