thorium(redirected from Thorium compounds)
Also found in: Thesaurus, Medical, Encyclopedia.
n. Symbol Th
A radioactive silvery-white metallic element that is recovered commercially from monazite. Its longest-lived isotope, the only one that occurs naturally, is Th-232 with a half-life of 14.1 billion years and is used as a nuclear fuel. Thorium is used in magnesium alloys, and its oxide is widely used in gas mantles of Welsbach burners. Atomic number 90; atomic weight 232.038; melting point 1,750°C; boiling point 4,788°C; specific gravity 11.72; valence 4. See 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.
(Elements & Compounds) a soft ductile silvery-white metallic element. It is radioactive and occurs in thorite and monazite: used in gas mantles, magnesium alloys, electronic equipment, and as a nuclear power source. Symbol: Th; atomic no: 90; atomic wt: 232.0381; half-life of most stable isotope, 232Th: 1.41 × 1010 years; valency: 4; relative density: 11.72; melting pt: 1755°C; boiling pt: 4788°C
[C19: New Latin, from Thor + -ium]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
tho•ri•um(ˈθɔr i əm, ˈθoʊr-)
a grayish white, lustrous, radioactive metallic element: used as a source of nuclear energy, in sun-lamp and vacuum-tube filaments, and in alloys. Symbol: Th; at. wt.: 232.038; at. no.: 90; sp. gr.: 11.7.
thor•ic (ˈθɔr ɪk, ˈθɒr-) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
Symbol Th A silvery-white, radioactive metallic element of the actinide series. It is used for fuel in some nuclear reactors and for improving the high-temperature strength of magnesium alloys. The only naturally occurring isotope of thorium is also its most stable, having a half-life of 14 billion years. Atomic number 90. 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.
Switch to new thesaurus
|Noun||1.||thorium - a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands|
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.
monazite - a reddish-brown mineral containing rare earth metals; an important source of thorium and cerium
thorite - a radioactive mineral consisting of thorium silicate; it is a source of thorium that is found in coarse granite
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
thorium[ˈθɔːrɪəm] N → torio 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
n (Chem) → Thorium nt
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007