Wikipedia

Boron

chemical element wi the atomic nummer o 5

Boron is a chemical element wi symbol B an atomic nummer 5. Acause boron is produced entirely bi cosmic ray spallation an nae bi stellar nucleosynthesis,[12] it is a law-abundance element in baith the solar seestem an the Yird's crust. Boron is concentratit on Yird bi the watter-solubility o its mair common naiturally occurrin compoonds, the borate minerals. Thir are mined industrially as evaporites, sic as borax an kernite.

Boron, 5B
Template:Infobox element/symbol-to-top-image/alt
boron (β-rhombohedral)[1]
Boron
Pronunciation/ˈbɔːrɒn/ ​(BOR-on)
Appearanceblack-broun
Standard atomic weight Ar, std(B)[10.806, 10.821] conventional: 10.81
Boron in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
-
↑
B
↓
Al
beryllium ← boron → carbon
Atomic nummer (Z)5
Groupgroup 13 (boron group)
Periodperiod 2
Blockp-block
Element category  Metalloid
Electron confeeguration[He] 2s2 2p1
Electrons per shell2, 3
Pheesical properties
Phase at STPsolit
Meltin pynt2349 K ​(2076 °C, ​3769 °F)
Bylin pynt4200 K ​(3927 °C, ​7101 °F)
Density when liquid (at m.p.)2.08 g/cm3
Heat o fusion50.2 kJ/mol
Heat o vapourisation480 kJ/mol
Molar heat capacity11.087 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2348 2562 2822 3141 3545 4072
Atomic properties
Oxidation states−5, −1, 0,[2] +1, +2, +3[3][4] (a mildly acidic oxide)
ElectronegativityPauling scale: 2.04
Ionisation energies
Atomic radiusempirical: 90 pm
Covalent radius84±3 pm
Van der Waals radius192 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o boron
Ither properties
Naitural occurrenceprimordial
Creestal structur ​rhombohedral
Rhombohedral creestal structur for boron
Speed o soond thin rod16,200 m/s (at 20 °C)
Thermal expansion(β form) 5–7[5] µm/(m·K) (at 25 °C)
Thermal conductivity27.4 W/(m·K)
Electrical resistivity~106  Ω·m (at 20 °C)
Magnetic orderindiamagnetic[6]
Mohs haurdness~9.5
CAS Nummer7440-42-8
History
DiskiveryJoseph Louis Gay-Lussac an Louis Jacques Thénard[7] (30 June 1808)
First isolationHumphry Davy[8] (9 Julie 1808)
Main isotopes o boron
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
10B 19.9(7)% stable[9]
11B 80.1(7)% stable[9]
10B content may be as low as 19.1% and as high as 20.3% in natural samples. 11B is the remainder in such cases.[10]
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References Eedit

  1. ↑ Van Setten et al. 2007, pp. 2460–1
  2. ↑ Braunschweig, H.; Dewhurst, R. D.; Hammond, K.; Mies, J.; Radacki, K.; Vargas, A. (2012). "Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond". Science. 336 (6087): 1420–2. Bibcode:2012Sci...336.1420B. doi:10.1126/science.1221138. PMID 22700924.
  3. ↑ Zhang, K.Q.; Guo, B.; Braun, V.; Dulick, M.; Bernath, P.F. (1995). "Infrared Emission Spectroscopy of BF and AIF" (PDF). J. Molecular Spectroscopy (in Inglis). 170 (1): 82. Bibcode:1995JMoSp.170...82Z. doi:10.1006/jmsp.1995.1058.
  4. ↑ Melanie Schroeder. "Eigenschaften von borreichen Boriden und Scandium-Aluminium-Oxid-Carbiden" (PDF) (in German). p. 139.
  5. ↑ Holcombe Jr., C. E.; Smith, D. D.; Lorc, J. D.; Duerlesen, W. K.; Carpenter; D. A. (October 1973). "Physical-Chemical Properties of beta-Rhombohedral Boron". High Temp. Sci. 5 (5): 349–57.CS1 maint: multiple names: authors leet (link)
  6. ↑ Lide, David R. (ed.) (2000). Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics (PDF). CRC press. ISBN 0849304814.CS1 maint: extra text: authors leet (link)
  7. ↑ Gay Lussac, J.L. and Thenard, L.J. (1808) "Sur la décomposition et la recomposition de l'acide boracique," Annales de chimie [later: Annales de chemie et de physique], vol. 68, pp. 169–174.
  8. ↑ Davy H (1809). "An account of some new analytical researches on the nature of certain bodies, particularly the alkalies, phosphorus, sulphur, carbonaceous matter, and the acids hitherto undecomposed: with some general observations on chemical theory". Philosophical Transactions of the Royal Society of London. 99: 33–104.
  9. ↑ a b "Atomic Weights and Isotopic Compositions for All Elements". National Institute of Standards and Technology. Retrieved 21 September 2008.
  10. ↑ Szegedi, S.; Váradi, M.; Buczkó, Cs. M.; Várnagy, M.; Sztaricskai, T. (1990). "Determination of boron in glass by neutron transmission method". Journal of Radioanalytical and Nuclear Chemistry Letters. 146 (3): 177. doi:10.1007/BF02165219.
  11. ↑ Zhang, K.Q.; Guo, B.; Braun, V.; Dulick, M.; Bernath, P.F. (1995). "Infrared Emission Spectroscopy of BF and AIF" (PDF). J. Molecular Spectroscopy. 170: 82. Bibcode:1995JMoSp.170...82Z. doi:10.1006/jmsp.1995.1058.CS1 maint: multiple names: authors leet (link)
  12. ↑ "Q & A: Where does the element Boron come from?". physics.illinois.edu. Archived frae the original on 29 Mey 2012. Retrieved 4 December 2011.
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