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61. PromethiumName: Promethium
Great care is required while handling promethium as a consequence of its radioactivity. Promethium salts luminesce in the dark with a pale blue or greenish glow, due to their high radioactivity. Ion-exchange methods led to the preparation of about 10 g of promethium from atomic reactor fuel processing wastes in early 1963. Little is yet generally known about the properties of metallic promethium. More than 30 promethium compounds have been prepared. Promethium is a rare earth metal. It appears that there is no known Pm existing in the earth's crust. The existence of promethium was first predicted by Bohuslav Brauner in 1902; this prediction was confirmed by Henry Moseley in 1914. Several groups claimed to have produced the element, but they could not confirm their discoveries because of the difficulty of separating promethium from other elements. Proof of the existence of promethium was obtained in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell during the analysis of byproducts of uranium fission; however, being too busy with defense-related research during World War II, they did not announce their discovery until 1947. The name "promethium" is derived from Prometheus from Greek mythology, who stole the fire of the sky and gave it to mankind. In 1963, ion-exchange methods were used to prepare about 10 g of promethium from atomic reactor fuel processing wastes. Today, promethium is still recovered from the byproducts of uranium fission; it can also be produced by bombarding 146Nd with neutrons, turning it into 147Nd which decays into 147Pm through beta decay with a half-life of 11 days. Great care is required while handling promethium as a consequence of its high radioactivity; in particular, promethium can emit X-rays during its beta decay. Note that its half-life is less than that of plutonium-239 by a factor of multiple thousands to tens of thousands. Promethium has no biological role. Quick links
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