Argon (Ar)

A colourless and odourless gaseous element that makes up 0.94% of the Earth’s atmosphere.

It will not support life or combustion, is very inert and is not known to form true chemical compounds. For that reason, it is widely used as an atmosphere for working with materials which are reactive when heated in air.

Argon is heavier than air and is obtained as a by-product of the liquefaction and separation of air.

Properties:

• Boiling Point: -186.0ºC
• Relative density 1.38 (Air = 1)
• Classification: Noble gas

Discovered in 1894 by Sir William Ramsay and named after the Greek word for inert: Argon.

See also liquid argon.