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plutonium
7 dictionary results for: Plutonium
Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This
plu·to·ni·um 
[ploo-toh-nee-uhm] Pronunciation Key
[ploo-toh-nee-uhm] Pronunciation Key –noun Chemistry, Physics.
| a transuranic element with a fissile isotope of mass number 239 (plutonium 239) that can be produced from non-fissile uranium 238, as in a breeder reactor. Symbol: Pu; atomic number: 94. |
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - Cite This Source - Share This
| plu·to·ni·um
(plōō-tō'nē-əm) Pronunciation Key
n. Symbol Pu A naturally radioactive, silvery, metallic transuranic element, occurring in uranium ores and produced artificially by neutron bombardment of uranium. Its longest-lived isotope is Pu 244 with a half-life of 76 million years. It is a radiological poison, specifically absorbed by bone marrow, and is used, especially the highly fissionable isotope Pu 239, as a reactor fuel and in nuclear weapons. Atomic number 94; melting point 640°C; boiling point 3,235°C; specific gravity 19.84; valence 3, 4, 5, 6. See Table at element. [After the dwarf planet Pluto (from the fact that it follows neptunium in the periodic table).] |
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The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Online Etymology Dictionary - Cite This Source - Share This
plutonium
plutonium
1942, from Pluto, the planet (see Pluto), the element named on suggestion of Seaborg and Wahl because it follows neptunium in the periodic table as Pluto follows Neptune in the Solar System.
Online Etymology Dictionary, © 2001 Douglas Harper
WordNet - Cite This Source - Share This
| plutonium | |
noun | |
| a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239 |
WordNet® 3.0, © 2006 by Princeton University.
The American Heritage Science Dictionary - Cite This Source - Share This
plutonium
(pl -tō'nē-əm) Pronunciation Key
Symbol Pu A silvery, radioactive metallic element of the actinide series that has the highest atomic number of all naturally occurring elements. It is found in minute amounts in uranium ores and is produced artificially by bombarding uranium with neutrons. It is absorbed by bone marrow and is highly poisonous. Plutonium is used in nuclear weapons and as a fuel in nuclear reactors. Its longest-lived isotope is Pu 244 with a half-life of 76 million years. Atomic number 94; melting point 640°C; boiling point 3,232°C; specific gravity 19.84; valence 3, 4, 5, 6. See Periodic Table. |
The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage New Dictionary of Cultural Literacy, Third Edition - Cite This Source - Share This
plutonium [(plooh-toh-nee-uhm)]
plutonium [(plooh-toh-nee-uhm)]
A radioactive chemical element that is artificially derived from uranium.
Note: Plutonium is used in nuclear reactors.
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage Stedman's Medical Dictionary - Cite This Source - Share This
plutonium plu·to·ni·um (pl&oomacr;-tō'nē-əm)
n.
Symbol Pu
A naturally radioactive, metallic transuranic element, occurring in uranium ores or produced artificially by neutron bombardment of uranium. Its longest-lived isotope is Pu 244 with a half-life of 77 million years. Atomic number 94; melting point 640°C; boiling point 3,228°C; specific gravity 19.84; valence 3, 4, 5, 6.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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