Àdàkọ:Infobox bórọ̀nù

Bórọ̀nù
5B
-

B

Al
bẹ́rílíọ̀mùbórọ̀nùcarbon
Ìhànsójú
black-brown
Àwọn ìdámọ́ wíwọ́pọ̀
Orúkọ, àmì-ìdámọ́, nọ́mbàbórọ̀nù, B, 5
Ìpèlóhùn /ˈbɔərɒn/
Ẹ̀ka ẹ́límẹ̀ntimẹ́tálọ́ìdì
Ẹgbẹ́, àsìkò, àdìpò13, 2, p
Ìwúwo átọ́mù10.81(1)
Ìtòléra ẹ̀lẹ́ktrónì[He] 2s2 2p1
2, 3
Electron shells of boron (2, 3)
Ìtàn
ÌwáríJoseph Louis Gay-Lussac and Louis Jacques Thénard[1] (30 June 1808)
Ìyàsọ́tọ̀ àkọ́kọ́Humphry Davy[2] (9 July 1808)
Physical properties
Phasealáralíle
Liquid density at m.p.2.08 g·cm−3
Melting point2349 K, 2076 °C, 3769 °F
Boiling point4200 K, 3927 °C, 7101 °F
Heat of fusion50.2
Heat of vaporization480 kJ·mol−1
Molar heat capacity11.087 J·mol−1·K−1
Vapor pressure
P (Pa)1101001 k10 k100 k
at T (K)234825622822314135454072
Atomic properties
Oxidation states3, 2, 1[3]
(mildly acidic oxide)
Electronegativity2.04 (Pauling scale)
Ionization energies
(more)
1st: 800.6 kJ·mol−1
2nd: 2427.1 kJ·mol−1
3rd: 3659.7 kJ·mol−1
Atomic radius90 pm
Covalent radius84±3 pm
Van der Waals radius192 pm
Miscellanea
Crystal structurerhombohedral
Bórọ̀nù has a rhombohedral crystal structure
Magnetic orderingdiamagnetic[4]
Electrical resistivity(20 °C) ~106 Ω·m
Thermal conductivity27.4 W·m−1·K−1
Thermal expansion(25 °C) (β form) 5–7[5] µm·m−1·K−1
Speed of sound (thin rod)(20 °C) 16,200 m·s−1
Mohs hardness~9.5
CAS registry number7440-42-8
Àwọn ísótòpù dídúró jùlọ
Main article: Àwọn ísótòpù bórọ̀nù
isoNAhalf-lifeDMDE (MeV)DP
10B19.9(7)%*10B is stable with 5 neutrons[6]
11B80.1(7)%*11B is stable with 6 neutrons[6]
*Boron-10 content may be as low as 19.1% and as
high as 20.3% in natural samples. Boron-11 is
the remainder in such cases.
[7]
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  • references

References

  1. 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.
  2. 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. http://books.google.com/books?id=gpwEAAAAYAAJ&pg=PA140#v=onepage&q&f=false. 
  3. Zhang, K.Q.; Guo, B.; Braun, V.; Dulick, M.; Bernath, P.F. (1995). "Infrared Emission Spectroscopy of BF and AIF". J. Molecular Spectroscopy 170: 82. 1995JMoSp.170...82Z. http://bernath.uwaterloo.ca/media/125.pdf. 
  4. Lide, David R. (ed.) (2000). Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics. CRC press. ISBN http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf. 
  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. 
  6. 6.0 6.1 "Atomic Weights and Isotopic Compositions for All Elements". National Institute of Standards and Technology. Retrieved 2008-09-21. 
  7. 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. 10.1007/BF02165219. 


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