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Syllabification: u·ra·ni·um
Pronunciation: /yo͝oˈrānēəm

Definition of uranium in English:


The chemical element of atomic number 92, a gray, dense 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

Example sentences
  • It is not possible, however, to construct weapons directly out of uranium or slightly enriched uranium.
  • All countries have uranium, uranium is a very common material around the world.
  • It is not certain if the effects are due to the chemical or the radioactive properties of uranium.


late 18th century: modern Latin, from Uranus + -ium.

Definition of uranium in:

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