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uranium

Pronunciation: /jʊˈreɪnɪəm/
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Definition of uranium

noun

[mass noun]
  • the chemical element of atomic number 92, a dense grey radioactive metal used as a fuel in nuclear reactors. (Symbol: 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

Origin:

late 18th century: modern Latin, from Uranus: compare with tellurium

uranium in other Oxford dictionaries

Definition of uranium in the US English dictionary
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