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Oxygen-related isotopologues of water include the commonly available form of heavy-oxygen water (H 2 18 O) and the more difficult to separate version with the 17 O isotope. Both elements may be replaced by isotopes, for example in the doubly labeled water isotopologue D 2 18 O.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
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.
Radioactive nonprimordial, but naturally occurring on Earth. 61 347 Carbon-14 (and other isotopes generated by cosmic rays) and daughters of radioactive primordial elements, such as radium, polonium, etc. 41 of these have a half life of greater than one hour. Radioactive synthetic half-life ≥ 1.0 hour). Includes most useful radiotracers. 662 989
Unstable isotopes decay through various radioactive decay pathways, most commonly alpha decay, beta decay, or electron capture. Many rare types of decay, such as spontaneous fission or cluster decay, are known. (See Radioactive decay for details.) [citation needed] Of the first 82 elements in the periodic table, 80 have isotopes considered to ...
Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).
Nitrogen-14 is the source of naturally-occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of 5700(30) years .
Radioactive isotopes ranging from 11 O to 28 O have also been characterized, all short-lived. The longest-lived radioisotope is 15 O with a half-life of 122.266(43) s, while the shortest-lived isotope is the unbound 11 O with a half-life of 198(12) yoctoseconds, though half-lives have not been measured for the unbound heavy isotopes 27 O and 28 ...