Argon (Ar) is a monatomic gas. The third constituent of air, it is among “noble gases”, along with Helium, Neon, Krypton and xenon, which constitute only 1% of the Earth’s atmosphere. Argon is the most abundant of noble gases, representing 0.9% of air. It is not considered as a reactive gas.
Argon was discovered in 1894 by Sir William Ramsay and Lord John Rayleigh.
To produce Argon, it is necessary to separate it from the other constituents of air, notably from Nitrogen (78%) and Oxygen (21%). Air is liquefied at a very low temperature (around -190°C). Its components (Nitrogen, Oxygen and noble gases) are then separated through cryogenic distillation.
At normal temperature and pressure, Argon is a colorless, odorless, and tasteless gas. It is chemically inert, which means it doesn’t react with any other element. For this reason, it is used as a protective atmosphere for a large number of industrial processes: steel manufacturing, welding, electronics, perishable foodstuffs preservation and even vintage wines protection.
It is also an efficient non-reactive thermal blanket. This property is useful notably for the filling of double glazing and, in the diving sector, to inflate waterproof wetsuits.