Atomic Number: 18
Atomic Weight: 39.948
Electron Configuration: 1s2 2s2p6 3s2p6
Group: Noble gases
Number of Protons/Electrons: 18
Isotops: Ar-36 (stable), Ar-37 (half-life 35 days), Ar-38 (stable), Ar-39 (half-life 269 years), Ar-40 (stable), Ar-41 (half-life 1.8 hours)
Crystal Structure: Cubic
Name Origin: from Greek: argos (inactive)
Argon (Ar) was discovered in 1894 by Sir William Ramsay and Lord Baron Rayleigh.
Argon makes up about 1% of the earth atmosphere.
Molecules of argon are mono-atomic: Ar.
Argon is a colorless, odorless, tasteless gas.
Argon is chemically inert.
Argon is extracted by Cryogenic Distillation of air.
Cryogenic distillation utilizes differences in boiling points of the air components.
The air is cooled down to the state of boiling liquid. The vapors are condensed and reboiled for several times. Compositions of the liquid and the vapors are different. This technique permits to separate air to its constituents: nitrogen, oxygen and argon.
Argon is used as an inert gas protecting liquid metals and hot metal parts from oxidation (Metal joining technologies (welding, brazing, soldering), Foundry technologies, growing semiconductor crystals).