- noun an inert gas, which occurs in air and of which isotopes form in the cooling systems of reactors. It is used in electric light bulbs.
- A noble gas which comprises approximately 0.93% of air by volume, and whose atomic number is 18. It has about 15 known isotopes, of which 3 are stable. It has various applications in electronics, including its use in specialized lamps, lasers, and in Geiger counters. Its chemical symbol is Ar.
- chemical symbolAr
(written as Argon)