Boron

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Boron,  5B
Boron mNACTEC.jpg
boron (β-rhombohedral)[1]
General properties
Appearance black-broun
Staundart atomic wecht (Ar, staundart) [10.80610.821] 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 Gold 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
berylliumboroncarbon
Atomic nummer (Z) 5
Group group 13 (boron group)
Period period 2
Element category   metalloid
Block p-block
Electron confeeguration [He] 2s2 2p1
Electrons per shell
2, 3
Pheesical properties
Phase (at STP) solit
Meltin pynt 2349 K ​(2076 °C, ​3769 °F)
Bylin pynt 4200 K ​(3927 °C, ​7101 °F)
Density when liquid (at m.p.) 2.08 g/cm3
Heat o fusion 50.2 kJ/mol
Heat o vapourisation 480 kJ/mol
Molar heat capacity 11.087 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 3, 2, 1[2] ​mildly acidic oxide
Electronegativity Pauling scale: 2.04
Ionisation energies
Atomic radius empirical: 90 pm
Covalent radius 84±3 pm
Van der Waals radius 192 pm
Color lines in a spectral range
Miscellanea
Crestal structur rhombohedral
Rhombohedral creestal structur for boron
Speed o soond thin rod 16,200 m/s (at 20 °C)
Thermal expansion (β form) 5–7[3] µm/(m·K) (at 25 °C)
Thermal conductivity 27.4 W/(m·K)
Electrical resistivity ~106  Ω·m (at 20 °C)
Magnetic orderin diamagnetic[4]
Mohs haurdness ~9.5
CAS Nummer 7440-42-8
History
Diskivery Joseph Louis Gay-Lussac an Louis Jacques Thénard[5] (30 June 1808)
First isolation Humphry Davy[6] (9 Julie 1808)
Main isotopes o boron
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
10B 19.9(7)% stable[7]
11B 80.1(7)% stable[7]
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.[8]
| references | in Wikidata

Boron is a chemical element wi seembol B an atomic nummer 5. Acause boron is produced entirely bi cosmic ray spallation an nae bi stellar nucleosynthesis,[9] 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.

References[eedit | eedit soorce]

  1. Van Setten et al. 2007, pp. 2460–1
  2. 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. 
  3. 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. 
  4. Lide, David R. (ed.) (2000). Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics (PDF). CRC press. ISBN 0849304814. 
  5. 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.
  6. 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. 
  7. 7.0 7.1 "Atomic Weights and Isotopic Compositions for All Elements". National Institute of Standards and Technology. Retrieved 2008-09-21. 
  8. 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. 
  9. "Q & A: Where does the element Boron come from?". physics.illinois.edu. Retrieved 2011-12-04.