Uranium the 92nd element and a member of Group 3b in the periodic table. Its atomic weight is 238.029. Its name and chemical symbol, U, are derived from Uranus, because that planet was discovered a few years before the discovery of the element. A compound of uranium (uranium oxide) was discovered in a uranium ore, pitchblende, by German chemist M. H. Klaproth in 1789. The German thought that he had found a new element. This was not …showed first 75 words of 519 total…

…showed last 75 words of 519 total…the Northern Territory of Australia, in Zaire, in France and a little in the United States. Approximately 90% of the remaining uranium minerals are uranyl compounds. No deposits of concentrated uranium ore have been discovered. As a result uranium must be extracted form ores containing less than 0.1% uranium, so that substantial, complex processing of the ores is required. Usually it is necessary to preconcentrate the ore by grinding and by the flotation process or similar processes.