Uranium
a metallic element, symbol U, atomic weight 238.5. Discovered in 1789 by Klaproth, in pitchblende, but first prepared in the pure state by Peligot, in 1840. Its principal ore is pitchblende, but it is also found in clevite, carnitite, samarskite, and fergusonite. It is a white metal, capable of taking a very high polish, with a density of 18.7.
It melts at a white heat, and can be distilled in the electric furnace. Chemically it is allied to chromium, molybdenum, and tungsten, and forms two series of salts, uranous and uranyl.