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The nuclides found naturally comprise not only the 286 primordials, but also include about 52 more short-lived isotopes (defined by a half-life less than 100 million years, too short to have survived from the formation of the Earth) that are daughters of primordial isotopes (such as radium from uranium); or else are made by energetic natural ...
A chart or table of nuclides maps the nuclear, or radioactive, behavior of nuclides, as it distinguishes the isotopes of an element.It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides that are variants of the same element) do not differ chemically to any significant degree, with the exception of hydrogen.
There are 28 known radioactive isotopes and 8 nuclear isomers, the most stable of which are 60 Fe (half-life 2.6 million years) and 55 Fe (half-life 2.7 years). Much of the past work on measuring the isotopic composition of iron has centered on determining 60 Fe variations due to processes accompanying nucleosynthesis (i.e., meteorite studies ...
Angiography is also commonly performed to identify vessels narrowing in patients with leg claudication or cramps, caused by reduced blood flow down the legs and to the feet; in patients with renal stenosis (which commonly causes high blood pressure) and can be used in the head to find and repair stroke. These are all done routinely through the ...
Archaeological materials, such as bone, organic residues, hair, or sea shells, can serve as substrates for isotopic analysis. Carbon, nitrogen and zinc isotope ratios are used to investigate the diets of past people; these isotopic systems can be used with others, such as strontium or oxygen, to answer questions about population movements and cultural interactions, such as trade.
The Segrè chart may be considered a map of the nuclear valley. The region of proton and neutron combinations outside of the valley of stability is referred to as the sea of instability. [4] [5] Scientists have long searched for long-lived heavy isotopes outside of the valley of stability, [6] [7] [8] hypothesized by Glenn T. Seaborg in the ...
Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various elements. Variations in isotopic abundance are measured by isotope-ratio mass spectrometry , and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between ...
There are two natural isotopes of iridium (77 Ir), and 37 radioisotopes, the most stable radioisotope being 192 Ir with a half-life of 73.83 days, and many nuclear isomers, the most stable of which is 192m2 Ir with a half-life of 241 years. All other isomers have half-lives under a year, most under a day.