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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.
One would expect that enrichment of heavy isotopes leads to progressively slower reactions, but the IsoRes hypothesis suggests that there exist certain resonance compositions for which kinetics increases even for higher abundances of heavy stable isotopes. For example, at 9.5% 13 C, 10.9% 15 N and 6.6% 18 O (when all three elements are 10-35 ...
In the case of the hydrogen isotope tritium (half-life = 12.3 years) and carbon-14 (half-life = 5,730 years), these isotopes derive their importance from all organic life containing hydrogen and carbon and therefore can be used to study countless living processes, reactions, and phenomena.
Isotopes of a chemical element differ only in the mass number. For example, the isotopes of hydrogen can be written as 1 H, 2 H and 3 H, with the mass number superscripted to the left. When the atomic nucleus of an isotope is unstable, compounds containing this isotope are radioactive. Tritium is an example of a radioactive isotope.
A medical isotope is an isotope used in medicine. The first uses of isotopes in medicine were in radiopharmaceuticals , and this is still the most common use. However more recently, separated stable isotopes have come into use.
Stable isotopes have the advantage of not delivering a radiation dose to the system being studied; however, a significant excess of them in the organ or organism might still interfere with its functionality, and the availability of sufficient amounts for whole-animal studies is limited for many isotopes.
Making a radiograph. Industrial radiography is a modality of non-destructive testing that uses ionizing radiation to inspect materials and components with the objective of locating and quantifying defects and degradation in material properties that would lead to the failure of engineering structures.
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear.