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[bawr-on, bohr-] /ˈbɔr ɒn, ˈboʊr-/
noun, Chemistry.
a nonmetallic element occurring naturally only in combination, as in borax or boric acid, and obtained in either an amorphous or a crystalline form when reduced from its compounds. Symbol: B; atomic weight: 10.811; atomic number: 5.
Origin of boron
1805-15; bor(ax1) + (carb)on
Related forms
[boh-ron-ik, baw-, buh-] /boʊˈrɒn ɪk, bɔ-, bə-/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for boron


a very hard almost colourless crystalline metalloid element that in impure form exists as a brown amorphous powder. It occurs principally in borax and is used in hardening steel. The naturally occurring isotope boron-10 is used in nuclear control rods and neutron detection instruments. Symbol: B; atomic no: 5; atomic wt: 10.81; valency: 3; relative density: 2.34 (crystalline), 2.37 (amorphous); melting pt: 2092°C; boiling pt: 4002°C
Word Origin
C19: from bor(ax) + (carb)on
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
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Word Origin and History for boron

1812, from borax + ending abstracted unetymologically from carbon (it resembles carbon). Originally called boracium by Humphrey Davy because it was drawn from boracic acid. Related: Boric.

Online Etymology Dictionary, © 2010 Douglas Harper
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boron in Medicine

boron bo·ron (bôr'ŏn')
Symbol B
A soft, amorphous or crystalline nonmetallic element, used in flares and nuclear reactor control rods. Atomic number 5; atomic weight 10.811; melting point 2,075°C; sublimation point 2,550°C; specific gravity (crystal) 2.34; valence 3.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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boron in Science
Symbol B
A shiny, brittle, black metalloid element extracted chiefly from borax. It is a good electrical conductor at high temperatures and a poor conductor at low temperatures. Boron is necessary for the growth of land plants and is used in the preparation of soaps, abrasives, and hard alloys. It is also used in the control rods of nuclear reactors as a neutron absorber. Atomic number 5; atomic weight 10.811; melting point 2,300°C; sublimation point 2,550°C; specific gravity (crystal) 2.34; valence 3. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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