Krypton (from Greek:κρυπτός kryptos "the hidden one") is a chemical element with symbol Kr and atomic number 36. It is a member of group 18 (noble gases) elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionally distilling liquefied air, and is often used with other rare gases in fluorescent lamps.
Three reasons Krypton stands out
- 1
Used in lasers and lighting, with a faint greenish light.
- 2
The metre was officially defined by a specific spectral line of this element from 1960 to 1983.
- 3
It is used in high-speed flash photography to capture images of extremely fast-moving objects.
A noble gas that can still make compounds
Krypton is scarce in air and chemically reserved, but “noble” does not mean absolutely inert. Under demanding conditions it forms compounds, especially with fluorine. Electrically excited krypton produces sharp spectral lines used in specialized lamps, lasers, and the historical definition of the metre.