Nickel Isotopes

Atoms of an element with the same number of protons but a different number of neutrons are known as isotopes. Nickel, atomic number (Z) = 28, has 28 protons in its nucleus. There are at least 30 isotopes of nickel, including the stable isotopes nickel-58, nickel-60, nickel-61, nickel-62 and nickel-64, and the radioactive isotopes nickel-56 and nickel-59.
Nickel-56 is produced in some supernovae in which nickel-56 then decays to cobalt-56 and then to iron-56. The half-life of nickel-56 is about 6 days.
Nickel-59 has been used to date the age of meteorites because it has a long half-life of 76,000 years.

Scientists from the Nuclear Spectroscopy Division at the Institute of Experimental Physics (IFD) of the Faculty of Physics, University of Warsaw (FUW) have undertaken research into nickel-48, a highly peculiar isotope which was only discovered in 1999. It has 28 protons and only 20 neutrons in its nucleus.

Nickel-48 is the most neutron deficient nucleus ever studied. Such an isotope "lives" only 2 thousandths of a second and then decays. The research by the Polish scientists from FUW has shown that the most frequent decay mode of nickel-48 is two-proton emission in which 2 protons are emitted from the nucleus. This simultaneous two-proton emission is a very rare phenomenon. So far it has only been observed in three other atomic nuclei: magnesium-19, zinc-54 and iron-45.

Reference
University of Faculty of Physics Warsaw (2011, June 9). Unique Polish detector can observe rare decays of nickel nuclei. ScienceDaily. Retrieved June 10, 2011, from http://www.sciencedaily.com­ /releases/2011/06/110609084811.htm

Further Reading
Isotopes
Nuclear Decay
Half-Life

Study Questions

1. What is the mass number of each of the following isotopes?
   
   • nickel-58
   • nickel-62
   • magnesium-19
   • zinc-54
   • iron-45
2. What is the atomic number of each of the following isotopes ?
   
   • nickel-58
   • nickel-62
   • magnesium-19
   • zinc-54
   • iron-45
3. How many protons are present in an atom of each of the following isotopes?
   
   • nickel-58
   • nickel-62
   • magnesium-19
   • zinc-54
   • iron-45
4. How many neutrons are present in an atom of each of the following isotopes?
   
   • nickel-58
   • nickel-62
   • magnesium-19
   • zinc-54
   • iron-45
5. Write nuclear decay equations for each of the following:
   
   • nickel-56 decays to cobalt-56
   • cobalt-56 decays to iron-56
   • nickel-48 decays by emitting 2 protons from the nucleus
   • magnesium-19 decays by emitting 2 protons from the nucleus
6. Using a half-life of 76,000 years for nickel-59, calculate how much nickel-59 will remain in a 50g pure sample in:
   • 38,000 years
   • 152,000 years
7. If a meteorite is approximately 1.2 million years old, what percentage of the original nickel-59 would remain?
8. If a meteorite has a mass of 600kg and contains 10% nickel-59, what mass of nickel-59 will remain in 380,000 years?