Krypton Basic Facts
- Atomic Number: 36
- Symbol: Kr
- Atomic Weight: 83.80
- Discovery: Sir William Ramsey, M.W. Travers, 1898 (Great Britain)
- Electron Configuration: Ar 4s2 3d10 4p6
- Word Origin: Greek kryptos: hidden
- Isotopes: There are 30 known isotopes of krypton ranging from Kr-69 to Kr-100. There are 6 stable isotopes: Kr-78 (0.35% abundance), Kr-80 (2.28% abundance), Kr-82 (11.58% abundance), Kr-83 (11.49% abundance), Kr-84 (57.00% abundance), and Kr-86 (17.30% abundance).
- Element Classification: Inert Gas
- Density: 3.09 g/cm3 (@4K - solid phase)
2.155 g/mL (@-153°C - liquid phase)
3.425 g/L (@25°C and 1 atm - gas phase)
Krypton Physical Data
- Melting Point (K): 116.6
- Boiling Point (K): 120.85
- Appearance: dense, colorless, odorless, tasteless gas
- Atomic Volume (cc/mol): 32.2
- Covalent Radius (pm): 112
- Specific Heat (@20°C J/g mol): 0.247
- Evaporation Heat (kJ/mol): 9.05
- Pauling Negativity Number: 0.0
- First Ionizing Energy (kJ/mol): 1350.0
- Oxidation States: 0, 2
- Lattice Structure: Face-Centered Cubic
- Lattice Constant (Å): 5.720
- CAS Registry Number: 7439-90-9
- Sir William Ramsay was awarded the 1904 Nobel Prize in Chemistry for the discovery of the noble gasses, including Krypton.
- The meter was defined in 1960 as 1,650,763.73 wavelengths of the 605.78-nanometer spectral line from Krypton-86. This standard was replaced in 1983.
- Krypton is usually inert, but it can form molecules. The first krypton molecule, krypton difluoride (KrF2), was discovered in 1963.
- Earth's atmosphere has approximately 1 part per million abundance of Krypton.
- Krypton can be obtained by fractional distillation from air.
- Light bulbs containing krypton gas can produce a bright white light useful for photography and runway lights.
- Krypton is often used in gas and gas ion lasers.
- Los Alamos National Laboratory (2001)
- Crescent Chemical Company (2001)
- Lange's Handbook of Chemistry (1952)
- CRC Handbook of Chemistry & Physics (18th Ed.) International Atomic Energy Agency ENSDF database (Oct 2010)