B Boron     Atomic number : 5 
    Relative atomic mass (12C = 12.0000) :  10.811 
    P H Y S I C A L     D A T A
Group 13 non-metal
 
Density / kg m-3 :  2340 (beta-rhomb.) [293 K]
 
Melting point / K :  2573 
 
Boiling point / K :  3931
 
    D I S C O V E R Y
Boron was discovered in 1808 by L.J. Lussac and L.J. Thenard in Paris, France and Sir Humphry Davy in London, England.
 
    G E O L O G I C A L     D A T A
Abundances
 
Sun (relative to H = 1 × 1012) : 2.63 × 105
 
Earth's crust / p.p.m. : 950
 
Residence time / years : 1 × 107
 
Classification : accumulating
 
Oxidation state : III
 
  
 
Seawater / p.p.m. : 4.41
    B I O L O G I C A L     D A T A
Level in humans
 
Blood / mg dm-3 : 0.13
 
Bone / p.p.m. : 1.1 - 3.3
 
Liver / p.p.m. : 0.4 - 3.3
 
Muscle / p.p.m. : 0.33 - 1
 
  
 
Daily dietary intake : 1 - 3 mg
 
Total mass of element
in average (70 kg) person :
18 mg

 

NetElements II  

A portrait of boron is available on the Visual Elements site. Up to 200 individual items of information on this element are available in The Elements.


Text copyright John Emsley 1999.   HTML and page layout copyright Simon Hall 1999.
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NetElements II last modified October 27th, 1999