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Isotopes of nickel
Naturally occurring nickel (28Ni) consists of five stable isotopes; 58Ni, 60Ni, 61Ni, 62Ni and 64Ni; 58Ni is the most abundant at over 68%. 26 radioisotopes have been characterized; the most stable are 59Ni with a half-life of 81,000 years, 63Ni with a half-life of 101 years, and 56Ni at 6.075 days. All the other radioactive isotopes have half-lives of less than 60 hours and most of these have half-lives of less than 30 seconds. This element also has 11 known meta states.
The known isotopes of nickel range in mass number from 48Ni to 82Ni, and include:
Nickel-48, discovered in 1999, is the most neutron-poor nickel isotope known. With 28 protons and 20 neutrons 48Ni is "doubly magic" (like 208
Pb) and therefore much more stable, with a half-life around 3 milliseconds, than would be expected from its position in the chart of nuclides. It has the highest ratio of protons to neutrons (proton excess) of any known doubly magic nuclide.
Nickel-56, also doubly magic, is produced in large quantities in supernovae. In the last phases of stellar evolution of very large stars, fusion of lighter elements like hydrogen and helium comes to an end. Later in the star's life cycle, elements including magnesium, silicon, and sulfur are fused to form heavier elements. Once the last nuclear fusion reactions cease, the star collapses to produce a supernova. During the supernova, silicon burning produces 56Ni. This isotope of nickel is favored because it has an equal number of neutrons and protons, making it readily produced by fusing two 28Si atoms. 56Ni is the last element that can be formed in the alpha process. Past 56Ni, nuclear reactions are endoergic and energetically unfavorable. 56Ni decays to 56Co and then 56Fe by β+ decay. The radioactive decay of 56Ni and 56Co supplies much of the energy for the light curves observed for stellar supernovae. The shape of the light curve of these supernovae display characteristic timescales corresponding to the decay of 56Ni to 56Co and then to 56Fe.
Nickel-58 is the most abundant isotope of nickel with a 68.077% natural abundance. It is the only isotope unstable toward double beta decay.
Nickel-59 is a long-lived cosmogenic radionuclide with a half-life of 81,000 years. 59Ni has found many applications in isotope geology. 59Ni has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment.
Nickel-60 is the daughter product of the extinct radionuclide 60
Fe (half-life 2.62 My). Because 60Fe has such a long half-life, its persistence in materials in the Solar System at high enough concentrations may have generated observable variations in the isotopic composition of 60Ni. Therefore, the abundance of 60Ni in extraterrestrial material may provide insight into the origin of the Solar System and its early history/very early history. Unfortunately, nickel isotopes appear to have been heterogeneously distributed in the early Solar System. Therefore, so far, no actual age information has been attained from 60Ni excesses. 60Ni is also the stable end-product of the decay of 60Zn, the last rung of the alpha ladder.
Nickel-61 is the only stable isotope of nickel with a nuclear spin (I = 3/2), which makes it useful for studies by EPR spectroscopy.
Isotopes of nickel
Naturally occurring nickel (28Ni) consists of five stable isotopes; 58Ni, 60Ni, 61Ni, 62Ni and 64Ni; 58Ni is the most abundant at over 68%. 26 radioisotopes have been characterized; the most stable are 59Ni with a half-life of 81,000 years, 63Ni with a half-life of 101 years, and 56Ni at 6.075 days. All the other radioactive isotopes have half-lives of less than 60 hours and most of these have half-lives of less than 30 seconds. This element also has 11 known meta states.
The known isotopes of nickel range in mass number from 48Ni to 82Ni, and include:
Nickel-48, discovered in 1999, is the most neutron-poor nickel isotope known. With 28 protons and 20 neutrons 48Ni is "doubly magic" (like 208
Pb) and therefore much more stable, with a half-life around 3 milliseconds, than would be expected from its position in the chart of nuclides. It has the highest ratio of protons to neutrons (proton excess) of any known doubly magic nuclide.
Nickel-56, also doubly magic, is produced in large quantities in supernovae. In the last phases of stellar evolution of very large stars, fusion of lighter elements like hydrogen and helium comes to an end. Later in the star's life cycle, elements including magnesium, silicon, and sulfur are fused to form heavier elements. Once the last nuclear fusion reactions cease, the star collapses to produce a supernova. During the supernova, silicon burning produces 56Ni. This isotope of nickel is favored because it has an equal number of neutrons and protons, making it readily produced by fusing two 28Si atoms. 56Ni is the last element that can be formed in the alpha process. Past 56Ni, nuclear reactions are endoergic and energetically unfavorable. 56Ni decays to 56Co and then 56Fe by β+ decay. The radioactive decay of 56Ni and 56Co supplies much of the energy for the light curves observed for stellar supernovae. The shape of the light curve of these supernovae display characteristic timescales corresponding to the decay of 56Ni to 56Co and then to 56Fe.
Nickel-58 is the most abundant isotope of nickel with a 68.077% natural abundance. It is the only isotope unstable toward double beta decay.
Nickel-59 is a long-lived cosmogenic radionuclide with a half-life of 81,000 years. 59Ni has found many applications in isotope geology. 59Ni has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment.
Nickel-60 is the daughter product of the extinct radionuclide 60
Fe (half-life 2.62 My). Because 60Fe has such a long half-life, its persistence in materials in the Solar System at high enough concentrations may have generated observable variations in the isotopic composition of 60Ni. Therefore, the abundance of 60Ni in extraterrestrial material may provide insight into the origin of the Solar System and its early history/very early history. Unfortunately, nickel isotopes appear to have been heterogeneously distributed in the early Solar System. Therefore, so far, no actual age information has been attained from 60Ni excesses. 60Ni is also the stable end-product of the decay of 60Zn, the last rung of the alpha ladder.
Nickel-61 is the only stable isotope of nickel with a nuclear spin (I = 3/2), which makes it useful for studies by EPR spectroscopy.
