neptunium

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nep·tu·ni·um

 (nĕp-to͞o′nē-əm, -tyo͞o′-)
n. Symbol Np
A silvery, metallic, naturally radioactive element, atomic number 93, the first of the transuranium elements. Its longest-lived isotope is Np-237 with a half-life of 2.1 million years. Found in trace quantities in uranium ores, it is produced synthetically by nuclear reactions. See Periodic Table.

[After the planet Neptune (from the fact that it follows uranium in the periodic table).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

neptunium

(nɛpˈtjuːnɪəm)
n
(Elements & Compounds) a silvery metallic transuranic element synthesized in the production of plutonium and occurring in trace amounts in uranium ores. Symbol: Np; atomic no: 93; half-life of most stable isotope, 237Np: 2.14 × 106 years; valency: 3, 4, 5, or 6; relative density: 20.25; melting pt: 639±1°C; boiling pt: 3902°C (est)
[C20: from Neptune2, the planet beyond Uranus, because neptunium is the element beyond uranium in the periodic table]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

nep•tu•ni•um

(nɛpˈtu ni əm, -ˈtyu-)

n.
a short-lived radioactive transuranic element produced in nuclear reactors by the neutron bombardment of U-238. Symbol: Np; at. no.: 93; at. wt.: 237.
[1940–45; Neptune + -ium2]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

nep·tu·ni·um

(nĕp-to͞o′nē-əm)
Symbol Np A silvery, radioactive metallic element of the actinide series. It occurs naturally in minute amounts in uranium ores and is produced artificially as a by-product of plutonium production. The most stable isotope of neptunium has a half-life of 2.1 million years. Atomic number 93. See Periodic Table.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.neptunium - a radioactive transuranic metallic elementneptunium - a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium
metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
Translations
нептуний
neptunium
neptunium
neptunio
neptuunium
neptunium
neptunium
neptunij
neptúnium
nettunio
ネプツニウム
neptunium
neptunium
neptun
neptuniu
neptunium
neptunij
neptunium
neptünyum

neptunium

[nepˈtjuːnɪəm] Nneptunio m
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005

neptunium

n (Chem) → Neptunium nt
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007