Argon (Ar) is a colorless, odorless, monatomic, highly unreactive gaseous element, which is the third most abundant
gas in the Earth's atmosphere (making
up approximately 1 percent of the atmosphere). It is obtained commercially
by fractionation of liquid air. Argon is the most abundant of the noble
gases (inert gases); it makes up 0.93% of the atmosphere by volume,
and 99.6% of this is the isotope 40Ar,
the remainder being 36Ar (0.34%) and 38Ar (0.06%).
It is used in electric light bulbs, fluorescent tubes, electronic valves,
argon lasers, and as an inert-gas shield in
arc-welding. Argon has no known true compounds.
|Argon. Credit: Pslawinski
The discovery of argon was announced Lord Rayleigh and William Ramsay at Oxford in 1894. Its
name comes from the Greek argos, meaning "inactive."
|relative atomic mass
|first ionization energy
Argon beam coagulator ablation is a procedure that destroys
tissue with an electrical current passed through a stream of argon gas to
the tissue. It is used to treat endometriosis and other conditions, and
to stop blood loss during surgery.