uranium
/jʊˈreɪnɪəm/noun
mass noun
- the chemical element of atomic number 92, a grey dense radioactive metal used as a fuel in nuclear reactors. (Symbol: U)（化学元素）铀（符号： U）。
Uranium is a chemically reactive metal belonging to the actinide series. Becquerel discovered radioactivity in uranium in 1896, and its capacity to undergo fission led to its use as a source of energy, though the fissile isotope, uranium-235, has to be separated from the more common uranium-238 before it can be used in nuclear weapons. The atom bomb exploded over Hiroshima in 1945 contained uranium-235.
词源
late 18th cent.: modern Latin, from Uranus： compare with TELLURIUM.