An island of inversion is a region of the
chart of nuclides that contains
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...
s with a non-standard ordering of single particle levels in the
nuclear shell model
In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels. The first shell m ...
. Such an area was first described in 1975 by French physicists carrying out
spectroscopic
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
mass measurements of exotic isotopes of lithium and sodium. Since then further studies have shown that five such regions exist within the known table of nuclides. These are centered at neutron-rich isotopes of five elements, namely
11Li,
20C,
31Na,
42Si, and
64Cr. Because there are five known islands of inversion, physicists have suggested renaming the phenomenon as an "archipelago of islands of shell breaking".
Studies with the purpose of defining the edges of this region are still ongoing.
See also
*
Table of nuclides
A table or chart of nuclides is a two-dimensional Cartesian coordinate system, graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol ''N'') and the other represents the number of protons (atomic number, sy ...
*
Periodic table and
Periodic table (extended)
*
Island of stability
References
External links
Abstract and references for the original paperArticle on archipelago of shell-breaking with map of nuclide table showing the 5 known islands''From Physical Review Letters: New neutron-rich nuclei support "island of inversion" theory''at the
National Superconducting Cyclotron Laboratory
The National Superconducting Cyclotron Laboratory (NSCL), located on the campus of Michigan State University was a isotope, rare isotope research facility in the United States.Bruns, Adam (January 2009How Are You Helping Companies Grow?''Site Sel ...
website
Nuclear physics
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