uranium

17 ENTRIES FOUND:

ura·ni·um

noun, often attributive \y-ˈrā-nē-əm\

: a radioactive element that is used to make nuclear energy and nuclear weapons

Full Definition of URANIUM

:  a silvery heavy radioactive polyvalent metallic element that is found especially in uraninite and exists naturally as a mixture of mostly nonfissionable isotopes — see element table

Origin of URANIUM

New Latin, from Uranus
First Known Use: circa 1797

Rhymes with URANIUM

ura·ni·um

noun \y-ˈrā-nē-əm\   (Medical Dictionary)

Medical Definition of URANIUM

: a silvery heavy radioactive polyvalent metallic element that is found especially in pitchblende and uraninite and exists naturally as a mixture of three isotopes of mass number 234, 235, and 238 in the proportions of 0.006 percent, 0.71 percent, and 99.28 percent respectively—symbol U; see element table

uranium

noun    (Concise Encyclopedia)

Chemical element of the actinide series (with many transition element properties), chemical symbol U, atomic number 92. A dense, hard, silvery white metal that tarnishes in air, it is isolated from such ores as pitchblende. Until the discovery of the first transuranium element in 1940, uranium was believed to be the heaviest element. Radioactivity was discovered in uranium by A.-H. Becquerel. All its isotopes are radioactive; several have half-lives long enough to permit determination of the age of the Earth by uranium-thorium-lead dating and uranium-234–uranium-238 dating. Nuclear fission was discovered in 1938 in uranium bombarded with neutrons, and the self-sustaining nuclear chain reaction, the atomic bomb, and the generation of nuclear power followed. Uranium has various valences in compounds, some of which have been used as colours in ceramic glazes, in lightbulb filaments, in photography, and as dyes and mordants.

Browse

Next Word in the Dictionary: uraniumaire
Previous Word in the Dictionary: uraninite
All Words Near: uranium

Seen & Heard

What made you want to look up uranium? Please tell us where you read or heard it (including the quote, if possible).

Get Our Free Apps
Voice Search, Favorites,
Word of the Day, and More
Join Us on FB & Twitter
Get the Word of the Day and More