thorium

[ thawr-ee-uhm, thohr- ]

/ ˈθɔr i əm, ˈθoʊr- /

noun Chemistry.

a grayish-white, lustrous, somewhat ductile and malleable, radioactive metallic element present in monazite: used as a source of nuclear energy, as a coating on sun-lamp and vacuum-tube filament coatings, and in alloys. Symbol: Th; atomic weight: 232.038; atomic number: 90; specific gravity: 11.7.

Compare thoria.

Origin of thorium

<New Latin (1829); see Thor, -ium

OTHER WORDS FROM thorium

thor·ic

[thawr-ik, thor-], /ˈθɔr ɪk, ˈθɒr-/, adjective

Words nearby thorium

Thorez, Thorfinn Karlsefni, thoria, thorianite, thorite, thorium, thorium dioxide, thorium series, thorn, thorn apple, thornback

Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for thorium

He was also the person who first identified silicon, selenium, thorium, and serium.
After Dominick|J. J. Berzelius|November 7, 2008|DAILY BEAST
But thorium mostly gives off the kind of radiation known as alpha particles.
Rip Foster in Ride the Gray Planet|Harold Leland Goodwin
The manufacturers give away a pound of cerium salts with every purchase of a hundred pounds of thorium salts.
Creative Chemistry|Edwin E. Slosson
Radium and thorium, but not uranium, give rise to radio-active gases which have been called emanations.
Darwin and Modern Science|A.C. Seward and Others

It will be seen that the ray of greatest range is that proceeding from thorium C2, which reaches a distance of 8.6 cms.
The Birth-Time of the World and Other Scientific Essays|J. (John) Joly
They would be compared with a chunk of thorium of the same size.
Rip Foster in Ride the Gray Planet|Harold Leland Goodwin

British Dictionary definitions for thorium

thorium

/ (ˈθɔːrɪəm) /

noun

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, 232 Th: 1.41 × 10 10 years; valency: 4; relative density: 11.72; melting pt: 1755°C; boiling pt: 4788°C

Derived forms of thorium

thoric, adjective

Word Origin for thorium

C19: New Latin, from Thor + -ium

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for thorium

thorium

[ thôr′ē-əm ]

n. Symbol Th

A radioactive metallic element that is used in magnesium alloys; its longest-lived isotope, Th 232, has a half-life of 1.41 X 1010 years. Atomic number 90.

Scientific definitions for thorium

thorium

[ thôr′ē-əm ]

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, Th 232, is also its most stable, having a half-life of 14.1 billion years. Atomic number 90; atomic weight 232.038; approximate melting point 1,750°C; approximate boiling point 4,500°C; approximate specific gravity 11.7; valence 4. See Periodic Table.

单词	thorium
释义	thorium [ thawr-ee-uhm, thohr- ] / ˈθɔr i əm, ˈθoʊr- / noun Chemistry. a grayish-white, lustrous, somewhat ductile and malleable, radioactive metallic element present in monazite: used as a source of nuclear energy, as a coating on sun-lamp and vacuum-tube filament coatings, and in alloys. Symbol: Th; atomic weight: 232.038; atomic number: 90; specific gravity: 11.7. Compare thoria. Origin of thorium <New Latin (1829); see Thor, -ium OTHER WORDS FROM thorium thor·ic [thawr-ik, thor-], /ˈθɔr ɪk, ˈθɒr-/, adjective Words nearby thorium Thorez, Thorfinn Karlsefni, thoria, thorianite, thorite, thorium, thorium dioxide, thorium series, thorn, thorn apple, thornback Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Example sentences from the Web for thorium He was also the person who first identified silicon, selenium, thorium, and serium. After Dominick\|J. J. Berzelius\|November 7, 2008\|DAILY BEAST But thorium mostly gives off the kind of radiation known as alpha particles. Rip Foster in Ride the Gray Planet\|Harold Leland Goodwin The manufacturers give away a pound of cerium salts with every purchase of a hundred pounds of thorium salts. Creative Chemistry\|Edwin E. Slosson Radium and thorium, but not uranium, give rise to radio-active gases which have been called emanations. Darwin and Modern Science\|A.C. Seward and Others It will be seen that the ray of greatest range is that proceeding from thorium C2, which reaches a distance of 8.6 cms. The Birth-Time of the World and Other Scientific Essays\|J. (John) Joly They would be compared with a chunk of thorium of the same size. Rip Foster in Ride the Gray Planet\|Harold Leland Goodwin British Dictionary definitions for thorium thorium / (ˈθɔːrɪəm) / noun 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, 232 Th: 1.41 × 10 10 years; valency: 4; relative density: 11.72; melting pt: 1755°C; boiling pt: 4788°C Derived forms of thorium thoric, adjective Word Origin for thorium C19: New Latin, from Thor + -ium Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Medical definitions for thorium thorium [ thôr′ē-əm ] n. Symbol Th A radioactive metallic element that is used in magnesium alloys; its longest-lived isotope, Th 232, has a half-life of 1.41 X 1010 years. Atomic number 90. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. Scientific definitions for thorium thorium [ thôr′ē-əm ] 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, Th 232, is also its most stable, having a half-life of 14.1 billion years. Atomic number 90; atomic weight 232.038; approximate melting point 1,750°C; approximate boiling point 4,500°C; approximate specific gravity 11.7; valence 4. See Periodic Table. The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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