Argon is used primarily in the welding industry because provides an inert atmosphere in which welded metals will not oxidize. It is odorless and colorless and is totally inert to other substances.
Argon makes up 0.94% of our atmosphere and the third most abundant gas in our atmosphere. The levels of Argon are gradually increasing due to radioactive potassium-40 which becomes Argon as it decays. Argon is acquired commercially by the distillation of liquid air.