86Kr

86Kr is a stable isotope of the noble gas krypton, with a mass number of 86 and atomic number 36. It is one of the six isotopes of krypton that occur naturally on Earth.

Natural krypton comprises several isotopes, and 86Kr accounts for roughly 17 percent of krypton in atmospheric samples. Krypton itself is present in the Earth's atmosphere at trace levels as a noble gas, and the isotopic composition is measured in geochemical and environmental studies.

Nuclear properties: 86Kr is an even-even nucleus (Z = 36, N = 50) and has a ground-state spin and parity of 0+. Its stability is aided by the closed neutron shell at N = 50, a magic number in the nuclear shell model. As a result, 86Kr is non-radioactive and does not decay under normal conditions.

Occurrence and synthesis: 86Kr occurs naturally in small but detectable amounts within atmospheric krypton and is also produced in astrophysical processes in stars. Industrially and scientifically, krypton (including 86Kr) is obtained from fractional distillation of liquid air for various applications.

Applications: Isotopic abundances of krypton, including 86Kr, are used in mass spectrometry and as tracers in environmental and atmospheric studies. Krypton isotope ratios help calibrate instruments, study atmospheric processes, and contribute to groundwater and paleoclimate investigations.

History: Krypton was discovered in 1898 by Sir William Ramsay and Morris Travers as a component of air. Subsequent isotopic analyses established the presence and stability of krypton isotopes, including 86Kr.