Argon (from the Greek word ?????, meaning "inactive") was suspected to be present in air by Henry Cavendish in 1785.
The isotope argon-39 has been used for groundwater dating and ice coring.
Argon constitutes 0.934 percent by volume and 1.29 percent by mass of the Earth's atmosphere, and air is the primary raw material used by industry to produce purified argon products.
The creation of argon hydrofluoride (HArF)—a metastable compound of argon with fluorine and hydrogen—was first reported by researchers at the University of Helsinki in 2000 (see Compounds below).
Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects.
Argon and oxygen are about equally soluble in water and are 2.5 times more soluble in water than nitrogen.
Argon (chemical symbol Ar, atomic number 18) is a member of the noble gas family of elements.
In 2005, the Huygens probe also discovered the presence of argon-40 on Titan, the largest moon of Saturn.
The inertness of argon is a very useful property for a number of applications.
By contrast, the Martian atmosphere contains 1.6 percent of argon-40 and five ppm of argon-36.
The extreme inertness of argon and other noble gases is attributed to the electronic structure of their atoms.
Argon was also encountered in 1882, by the independent research of H.F. Newall and W.N.
By shining ultraviolet light onto frozen argon containing a small amount of hydrogen fluoride, argon hydrofluoride (HArF) was formed.
Theoretical calculations (by computer) have shown several argon compounds that should be stable but for which no synthesis routes are currently known.
In 2000, the first argon compounds were formed by researchers at the University of Helsinki.
Argon is usually isolated by the technique of fractional distillation of liquefied air.
Argon became the first member of the noble gases to be discovered.
The main isotopes of argon found on Earth are 40Ar, 36Ar, and 38Ar.
Argon is colorless and odorless in both its liquid and gaseous forms.
Argon, an extremely unreactive element, is a member of the noble gas series in the periodic table.
* Argon is used in electrical light bulbs, fluorescent tubes, photo tubes, and glow tubes at a pressure of about 3 mm. *Argon is used as a motionless gas shield for arc welding and cutting. *Argon can serve as a blanket for the production of titanium and other reactive elements.