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Due to its natural abundance and half-life relative to other radioactive elements, 238 U produces ~40% of the radioactive heat produced within the Earth. [2] The 238 U decay chain contributes six electron anti-neutrinos per 238 U nucleus (one per beta decay), resulting in a large detectable geoneutrino signal when decays occur within the Earth. [3]
Uranium–uranium dating is a radiometric dating technique which compares two isotopes of uranium (U) in a sample: uranium-234 (234 U) and uranium-238 (238 U). It is one of several radiometric dating techniques exploiting the uranium radioactive decay series, in which 238 U undergoes 14 alpha and beta decay events on the way to the stable isotope 206 Pb.
The existence of two 'parallel' uranium–lead decay routes (238 U to 206 Pb and 235 U to 207 Pb) leads to multiple feasible dating techniques within the overall U–Pb system. The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below). However, use of a single decay scheme (usually 238 ...
One of its great advantages is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 700 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample ...
234 U occurs in natural uranium as an indirect decay product of uranium-238, but makes up only 55 parts per million of the uranium because its half-life of 245,500 years is only about 1/18,000 that of 238 U. The path of production of 234 U is this: 238 U alpha decays to thorium-234. Next, with a short half-life, 234 Th beta decays to ...
Uranium-234 is a member of the uranium series and occurs in equilibrium with its progenitor, 238 U; it undergoes alpha decay with a half-life of 245,500 years [7] and decays to lead-206 through a series of relatively short-lived isotopes. Uranium-233 undergoes alpha decay with a half-life of 160,000 years and, like 235 U, is fissile. [12]
Radioactive isotope table "lists ALL radioactive nuclei with a half-life greater than 1000 years", incorporated in the list above. The NUBASE2020 evaluation of nuclear physics properties F.G. Kondev et al. 2021 Chinese Phys. C 45 030001. The PDF of this article lists the half-lives of all known radioactives nuclides.
The U–Pb dating method can yield the most precise ages for early Solar System objects due to the optimal half-life of 238 U. However, the absence of zircon or other uranium-rich minerals in chondrites, and the presence of initial non-radiogenic Pb (common Pb), rules out direct use of the U–Pb concordia method.