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uranium

[yoo-rey-nee-uh m] /yʊˈreɪ ni əm/
noun, Chemistry
1.
a white, lustrous, radioactive, metallic element, occurring in pitchblende, and having compounds that are used in photography and in coloring glass. The 235 isotope is used in atomic and hydrogen bombs and as a fuel in nuclear reactors. Symbol: U; atomic weight: 238.03; atomic number: 92; specific gravity: 19.07.
Origin
1790-1800
1790-1800; < Neo-Latin; see Uranus, -ium
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Based on the Random House Dictionary, © Random House, Inc. 2014.
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Examples from the web for uranium
  • The uranium fire in an atomic reactor is both ignited and sustained by neutrons.
  • If the fuel gets hot enough, the uranium can melt, eventually falling to the bottom of the reactor and even burning through it.
  • It also seeks to eliminate the use of weapons-grade uranium in making the isotopes.
  • To make atoms heavier than that, physicists must bombard uranium with neutrons, or squash smaller atoms together.
  • And especially, check out depleted uranium munitions.
  • Later that same year, after bombarding uranium with neutrons, they found barium.
  • Nuclear reactors are powered by the fission of a radioactive element, typically uranium.
  • Mining companies use microbes to recover metals such as gold, copper and uranium.
  • Depleted uranium was found in many areas, including the one pictured.
  • Enriching raw uranium is more expensive than converting highly enriched uranium to fuel grade.
British Dictionary definitions for uranium

uranium

/jʊˈreɪnɪəm/
noun
1.
a radioactive silvery-white metallic element of the actinide series. It occurs in several minerals including pitchblende, carnotite, and autunite and is used chiefly as a source of nuclear energy by fission of the radioisotope uranium-235. Symbol: U; atomic no: 92; atomic wt: 238.0289; half-life of most stable isotope, 238U: 451 × 109 years; valency: 2-6; relative density: 18.95 (approx.); melting pt: 1135°C; boiling pt: 4134°C
Word Origin
C18: from New Latin, from Uranus²; from the fact that the element was discovered soon after the planet
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for uranium
n.

rare metallic element, 1797, named 1789 in Modern Latin by its discoverer, German chemist and mineralogist Martin Heinrich Klaproth (1743-1817), for the recently found planet Uranus (q.v.).

Online Etymology Dictionary, © 2010 Douglas Harper
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uranium in Medicine

uranium u·ra·ni·um (yu-rā'nē-əm)
n.
Symbol U
An easily oxidized radioactive toxic metallic element having 16 known isotopes, of which U 238 is the most naturally abundant. Atomic number 92; atomic weight 238.03; melting point 1,135°C; boiling point 4,151°C; specific gravity 18.95; valence 2, 3, 4, 5, 6.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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uranium in Science
uranium
  (y-rā'nē-əm)   
Symbol U
A heavy, silvery-white, highly toxic, radioactive metallic element of the actinide series. It has 14 known isotopes, of which U 238 is the most naturally abundant, occurring in several minerals. Fissionable isotopes, especially U 235, are used in nuclear reactors and nuclear weapons. Atomic number 92; atomic weight 238.03; melting point 1,132°C; boiling point 3,818°C; specific gravity 18.95; valence 2, 3, 4, 5, 6. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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uranium in Culture

uranium definition


A chemical element that is naturally radioactive. An isotope of uranium, uranium 235, is the main fuel for nuclear reactors and atomic bombs. Its symbol is U. (See fission and chain reaction.)

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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