uranium

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uranium

 [u-ra´ne-um]
a chemical element, atomic number 92, atomic weight 238.03, symbol U. (See Appendix 6.)

u·ra·ni·um (U),

(yū-rā'nē-ŭm),
A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: 238U and 235U (99.2745% and 0.720%, respectively, the rest being made up by 234U), 235U being the first substance ever shown capable of supporting a self-sustaining chain reaction.
[G. myth. character, Uranus]

u·ra·ni·um

(U) (yŭr-ā'nē-ŭm)
A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: 238U and 235U (99.2745% and 0.720%, respectively, the rest being made up by 234U), 235U being the first substance ever shown capable of supporting a self-sustaining chain reaction.
[G. myth. character, Uranus]
References in periodicals archive ?
Both of these take advantage of the difference in mass between uranium 238 and uranium 235, to separate the two isotopes.
When we combine these vectors with the administration of experimental, genetically engineered vaccines and a field of radiation from Uranium 238 weapons, the assault on the immune system is heightened far beyond even the sum of each of those causes taken separately.
But 99 percent of this uranium is composed of the isotope called uranium 238; its lighter-weight isotope, uranium 235, is the crucial material whose atoms can split and release energy for power plants or bombs.
A little stunned by the thought of 10-year-olds toying with vials of uranium 238, I tell Pam Vorachek, "He had high expectations of kids."
Another advantage of GT-MHRs is their great "plutonigenic" efficiency (90% burned), and the fact that such reactors would not generate plutonium, unlike "classic" atomic reactors.Plutonium 239 does not exist in nature but is produced in reactors from uranium 238. Reprocessed, it can be used in certain reactors as a uranium-plutonium mixture (MOX), or in fast breeder reactors.