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The Suess effect is a change in the ratio of the atmospheric concentrations of heavy isotopes of carbon (13 C and 14 C) by the admixture of large amounts of fossil-fuel derived CO 2, which contains no 14 CO 2 and is depleted in 13 CO 2 relative to CO 2 in the atmosphere and carbon in the upper ocean and the terrestrial biosphere . [1]
The next group is the primordial radioactive nuclides. These have been measured to be radioactive, or decay products have been identified in natural samples (tellurium-128, barium-130). There are 35 of these (see these nuclides), of which 25 have half-lives longer than 10 13 years. With most of these 25, decay is difficult to observe and for ...
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.
Technetium is a silvery-gray radioactive metal with an appearance similar to platinum, commonly obtained as a gray powder. [25] The crystal structure of the bulk pure metal is hexagonal close-packed , and crystal structures of the nanodisperse pure metal are cubic .
Some radionuclides, such as cobalt-60 and iridium-192, are made by the neutron irradiation of normal non-radioactive cobalt and iridium metal in a nuclear reactor, creating radioactive nuclides of these elements which contain extra neutrons, compared to the original stable nuclides. In addition to their uses in radiography, both cobalt-60 (60 Co
In a fission nuclear reactor, uranium-238 can be used to generate plutonium-239, which itself can be used in a nuclear weapon or as a nuclear-reactor fuel supply. In a typical nuclear reactor, up to one-third of the generated power comes from the fission of 239 Pu, which is not supplied as a fuel to the reactor, but rather, produced from 238 U. [5] A certain amount of production of 239
Induced radioactivity, also called artificial radioactivity or man-made radioactivity, is the process of using radiation to make a previously stable material radioactive. [1] The husband-and-wife team of Irène Joliot-Curie and Frédéric Joliot-Curie discovered induced radioactivity in 1934, and they shared the 1935 Nobel Prize in Chemistry ...
Three isotopes, 225 Ac, 227 Ac and 228 Ac, were found in nature and the others were produced in the laboratory; only the three natural isotopes are used in applications. Actinium-225 is a member of the radioactive neptunium series; [60] it was first discovered in 1947 as a decay product of uranium-233 and