The element krypton is used as a low-pressure filling gas for fluorescent lights. It is also used in certain photographic flash lamps for high-speed photography. Krypton can be combined with other gases to make luminous signs that glow with a greenish-yellow light.
Krypton is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere. It is isolated by fractionally distilling liquefied air, and is often used with other rare gases in fluorescent lamps. Krypton is inert for most practical purposes, except with fluorine gas. But it is reactive enough to form chemical compounds. Radioactive krypton was used to estimate Soviet nuclear production.
Krypton is characterized by several sharp emission lines, with the strongest being green and yellow. It is one of the products of uranium fission. Solidified krypton is white and crystalline with a face-centered cubic crystal structure, which is a common property of all noble gases.
Krypton has a narcotic potency seven times greater than air, so breathing a gas containing 50 percent krypton and 50 percent air would cause narcosis similar to breathing air at four times atmospheric pressure.
The amount of krypton in space is uncertain, as the amount is derived from meteoric activity and from solar winds. The first measurements suggest an overabundance of krypton in space.