uranium, U, atomic number 92(noun)
a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
The element with atomic number 92 and symbol U.
Origin: After Uranus (the planet).
an element of the chromium group, found in certain rare minerals, as pitchblende, uranite, etc., and reduced as a heavy, hard, nickel-white metal which is quite permanent. Its yellow oxide is used to impart to glass a delicate greenish-yellow tint which is accompanied by a strong fluorescence, and its black oxide is used as a pigment in porcelain painting. Symbol U. Atomic weight 239.
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with symbol U and atomic number 92. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all its isotopes are unstable. The most common isotopes of uranium are uranium-238 and uranium-235. Uranium has the second highest atomic weight of the primordially occurring elements, lighter only than plutonium. Its density is about 70% higher than that of lead, but not as dense as gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238, uranium-235, and a very small amount of uranium-234. Uranium decays slowly by emitting an alpha particle. The half-life of uranium-238 is about 4.47 billion years and that of uranium-235 is 704 million years, making them useful in dating the age of the Earth. Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology. While uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons, uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors, and produces the fissile material for nuclear weapons. Depleted uranium is used in kinetic energy penetrators and armor plating.
Chambers 20th Century Dictionary
ū-rā′ni-um, n. a very hard but moderately malleable metal, resembling nickel or iron in its lustre and colour, but in a finely comminuted state occurring as a black powder.—adj. Urā′nic. [Gr. ouranos, heaven.]
U.S. National Library of Medicine
Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.
Is a chemical element.
Uranium is used in nuclear power and nuclear fuel.
The numerical value of uranium in Chaldean Numerology is: 7
The numerical value of uranium in Pythagorean Numerology is: 7
Sample Sentences & Example Usage
We have always said the U.S. is responsible for the cleanup of uranium legacy sites.
In particular, they are useful when working with higher enrichment such as 20 percent enriched uranium.
One possibility is that North Korea will enrich the uranium to expand its stockpile of nuclear weapons.
It is necessary to identify where North Korea enriches uranium and part of that is understanding where it has done it in the past.
It keeps the infrastructure in place and keeps a leg up, if Senator Graham and Senator Menendez want to restart [ uranium ] enrichment operations.
Images & Illustrations of uranium
Translations for uranium
From our Multilingual Translation Dictionary
- uraniCatalan, Valencian
- uraniumWestern Frisian
- uràiniamScottish Gaelic
- ウラン, 鈾Japanese
- 우란, 우라늄Korean
- UranLuxembourgish, Letzeburgesch
- uraan, uraniumDutch
- uranNorwegian Nynorsk
- łéétsohNavajo, Navaho
- уран, uranij, ураниј, uranSerbo-Croatian
- уран, uranUzbek
- uran, uraniVietnamese
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