ura·ni·um /jʊˈrenɪəm/ 名詞
U·ra·ni·um n. Chem. An element of the chromium group, found in certain rare minerals, as pitchblende, uranite, etc., and reduced as a heavy, hard, nickel-white metal which is quite permanent. Its yellow oxide is used to impart to glass a delicate greenish-yellow tint which is accompanied by a strong fluorescence, and its black oxide is used as a pigment in porcelain painting. Symbol U. Atomic weight 239.
Note: ☞ Uranium was discovered in the state of an oxide by Klaproth in 1789, and so named in honor of Herschel's discovery of the planet Uranus in 1781.
n : a heavy toxic silvery-white radioactive metallic element;
occurs in many isotopes; used for nuclear fuels and
nuclear weapons [syn: U, atomic number 92]
Atomic number: 92
Atomic weight: (231)
White radioactive metallic element belonging to the actinoids. Three
natural isotopes, U-238, U-235 and U-234. Uranium-235 is used as the fuel
for nuclear reactors and weapons. Discovered by Martin H. Klaproth in 1789.