Krypton is a rare and inert gas and belong to the Nobel gases. It was discovered by Sir William Ramsay in 1898. It emits unique and sharp spectral lines and is widely used in high speed photography and lasers.
History and Discovery
Krypton was discovered by Sir William Ramsay and Morris Travers in 1898, as a residual gas in a chamber after all components of liquid air have been evaporated. Ramsay received the Nobel prize in Chemistry in 1904 for his contributions in the discovery of krypton and other noble gases, except radon. Before its discovery, Ramsay believed that in nature, often element hides in another. And the gap between argon and helium in the periodic table made him look closely within elements. The name krypton has been derived from the Greek word, kryptos, that means “hidden” .
Krypton is a rare gas. It is present in about 1ppm in the Earth’s atmosphere. Krypton is obtained by fractional distillation of liquid air. Krypton is found in abundance in space. Krypton is also produced during the uranium fission reaction .
Krypton is colorless and odorless gas. Krypton in solid state is white and have a cubical structure. Krypton gives two distinct lines of green and yellow color in its emission spectrum . Krypton has a density of 3.749 g/L at standard conditions and is almost three times denser than air. Krypton is affected by an external magnetic field and is diamagnetic. Krypton is highly volatile and quickly vaporizes when exposed to water.
Krypton is chemically inactive. However, under extreme conditions, it reacts with fluorine and forms krypton difluoride (KrF2). It is a crystalline white solid and is stable at low temperature. Crystals of krypton hydride can be formed under increased pressure, i.e. above 5GPa. Krypton has two oxidation states .
Significance and Uses
- Krypton is widely used in photography. It is used flash lamps for high speed photography.
- It is used for making energy-efficient fluorescent lamps.
- Krypton is also used in high-powered flash lamps on airport runways.
- Krypton is used in making high powered gas lasers and krypton fluoride is used in some lasers.
- Krypton-85 is used a marker for the detection of nuclear weapon production and research facilities.
- Krypton is used in making flash signs like luminous neon light signs, that glow with a distinct green yellow light.
- Krypton emits a shaper red light and is used for making red lasers used in high power laser shows.
- Krypton fluoride lasers are also used in research involving nuclear fusion reactions for the generation of energy.
- The international unit of meter in System International use the wavelength of light emitted by krypton isotope, 86Kr, to define distance of one meter.
Krypton is non-toxic in nature. If inhaled in high concentrations, it can act as an asphyxiant and displace the normal concentration of oxygen in the lungs. This can lead to breathing difficulty and lead to drowsiness and unconsciousness.
Isotopes of Krypton
There are 25 isotopes of krypton, with mass number ranging from 71 to 95. There are six stable isotopes in the naturally occurring krypton. These include krypton-78, krypton-80, krypton-82, krypton-83, krypton-84, krypton-84, krypton-86. Krypton-84 is the most abundant isotope, 57%. There are around thirty artificial isotopes of krypton. Krypton-81 and krypton-85 are radioactive isotopes of krypton but have considerably long half-lives .
. William Ramsay; Morris W. Travers (1898). “On a New Constituent of Atmospheric Air”. Proceedings of the Royal Society of London. 63 (1): 405–408. doi:10.1098/rspl.1898.0051.
. “Krypton” (PDF). Argonne National Laboratory, EVS. 2005. Archived from the original (PDF) on 2009-12-20. Retrieved 2007-03-17.
. “Spectra of Gas Discharges”.
. Kleppe, Annette K.; Amboage, Mónica; Jephcoat, Andrew P. (2014). “New high-pressure van der Waals compound Kr(H2)4 discovered in the krypton-hydrogen binary system”. Scientific Reports. 4. Bibcode:2014NatSR…4E4989K. doi:10.1038/srep04989.