boron

[bawr-on, bohr-]
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:
1805–15; bor(ax1) + (carb)on

boronic [boh-ron-ik, baw-, buh-] , adjective
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World English Dictionary
boron (ˈbɔːrɒn)
 
n
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
 
[C19: from bor(ax) + (carb)on]

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Etymonline
Word Origin & History

boron
1812, from borax + ending abstracted unetymologically from carbon (it resembles carbon). Originally called boracium by Sir Humphrey Davy because it was drawn from boracic acid. Related: Boric.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Medical Dictionary

boron bo·ron (bôr'ŏn')
n.
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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American Heritage
Science Dictionary
boron   (bôr'ŏn')  Pronunciation Key 
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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Example sentences
The team injected boron water into the reactor to slow what workers feared was
  a runaway reaction.
Researchers sponsored by them came up with a non-toxic, low-temperature glaze
  based on boron.
These rods, made of neutron-absorbing materials such as boron, mop up excess
  neutrons and quench the chain reaction.
Adding atoms of boron or nitrogen enables the diamond film to conduct
  electricity.
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