Search results
Results from the WOW.Com Content Network
Caesium (IUPAC spelling; [9] also spelled cesium in American English) is a chemical element; it has symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F; 301.6 K), which makes it one of only five elemental metals that are liquid at or near room temperature .
Caesium-137 (137 55 Cs), cesium-137 (US), [7] or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is ...
As caesium 133, 135, and 137 are formed by the beta particle decay of the corresponding xenon isotopes, this causes the caesium to become physically separated from the bulk of the uranium oxide fuel. Because 135 Xe is a potent nuclear poison with the largest cross section for thermal neutron absorption, the buildup of 135 Xe in the fuel inside ...
Almost all caesium produced from nuclear fission comes from beta decay of originally more neutron-rich fission products, passing through isotopes of iodine then isotopes of xenon. Because these elements are volatile and can diffuse through nuclear fuel or air, caesium is often created far from the original site of fission.
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 include jumping up and down make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
In addition to their uses in radiography, both cobalt-60 (60 Co) and iridium-192 (192 Ir) are used in the radiotherapy of cancer. Cobalt-60 tends to be used in teletherapy units as a higher photon energy alternative to caesium-137, while iridium-192 tends to be used in a different mode of therapy, internal radiotherapy or brachytherapy.
Selenium, which is an essential element for animals and prokaryotes and is a beneficial element for many plants, is the least-common of all the elements essential to life. [ 3 ] [ 63 ] Selenium acts as the catalytic center of several antioxidant enzymes, such as glutathione peroxidase , [ 11 ] and plays a wide variety of other biological roles .
Pure strontium is used in the study of neurotransmitter release in neurons. [76] [77] Radioactive strontium-90 finds some use in RTGs, [78] [79] which utilize its decay heat. Barium is used in vacuum tubes as a getter to remove gases. [61] Barium sulfate has many uses in the petroleum industry, [4] [80] and other industries. [4] [61] [81]