|Type:Noble Gas||Atomic weight:83.80|
|Density @ 293 K: 0.003708 g/cm3||Atomic volume:38.9 cm3/mol|
William Ramsay and Morris Travers discovered krypton in 1898. They discovered it in the residue remaining after liquid air had been fractionally distilled. With the oxygen and nitrogen gone, a bright yellow spectral line that was neither sodium nor helium revealed the presence of a new element. The element name comes from the Greek word 'kryptos', meaning hidden.
|State (s, l, g):gas|
|Melting point:115.9 K (-157.3 °C)||Boiling point:119.4 K (-153.2 °C)|
|Specific heat capacity:0.248 J g-1 K-1||Heat of atomization:0 kJ mol-1|
|Heat of fusion: 1.638 kJ mol-1||Heat of vaporization :9.029 kJ mol-1|
|1st ionization energy:1350.7 kJ mol-1||2nd ionization energy:2350.3 kJ mol-1|
|3rd ionization energy:3565.1 kJ mol-1||Electron affinity:kJ mol-1|
|Shells:2,8,18,8||Electron configuration:[Ar] 3d10 4s2 4p6|
|Minimum oxidation number:0||Maximum oxidation number:2|
|Min. common oxidation no.:0||Max. common oxidation no.:2|
|Electronegativity (Pauling Scale): 3||Polarizability volume:2.5 Å3|
|Structure:fcc: face-centered cubic||Color:Colorless|
Krypton is considered to be non-toxic.
Krypton is a colorless, odorless, inert gas.
Krypton is used in lighting products. Ionized krypton gas appears whitish - see photo on left - which makes krypton-based bulbs useful as a brilliant white light source in high speed photography. An important lighting use is also in high-powered, flashing airport runway lights.
|Reaction with air:none||Reaction with 6 M HCl:none|
|Reaction with 15 M HNO3:none||Reaction with 6 M NaOH:none|
|Atomic radius:88 pm||Ionic radius (1+ ion):pm|
|Ionic radius (2+ ion):pm||Ionic radius (3+ ion):pm|
|Ionic radius (2- ion):pm||Ionic radius (1- ion):pm|
|Thermal conductivity:0.01 W m-1 K-1||Electrical conductivity:S cm-1|
|Abundance earth's crust: 100 parts per trillion by weight, 30 parts per trillion by moles|
|Abundance solar system:parts per million by weight, parts per million by moles|
|Cost, pure:$33 per 100g|
|Cost, bulk:$ per 100g|
Krypton is obtained commercially by fractional distillation of liquid air.
Krypton has 25 isotopes whose half-lives are known, with mass numbers 71 to 95. Of these, six are stable: 78Kr, 80Kr, 82Kr, 83Kr, 84Kr and 86Kr. The most abundant isotope is 84Kr at 57.03%.