Bórọ̀nù

Lát'ọwọ́ Wikipedia, ìwé ìmọ̀ ọ̀fẹ́
Lọ sí: atọ́ka, àwárí
Bórọ̀nù
5B
-

B

Al
bẹ́rílíọ̀mùbórọ̀nùcarbon
Ìhànsójú
black-brown
Àwọn ìdámọ́ wíwọ́pọ̀
Orúkọ, àmì-ìdámọ́, nọ́mbà bórọ̀nù, B, 5
Ìpèlóhùn /ˈbɔərɒn/
Ẹ̀ka ẹ́límẹ̀nti mẹ́tálọ́ìdì
Ẹgbẹ́, àsìkò, àdìpò 132, p
Ìwúwo átọ́mù 10.81(1)
Ìtòléra ẹ̀lẹ́ktrónì [He] 2s2 2p1
2, 3
Electron shells of boron (2, 3)
Ìtàn
Ìwárí Joseph Louis Gay-Lussac and Louis Jacques Thénard[1] (30 June 1808)
Ìyàsọ́tọ̀ àkọ́kọ́ Humphry Davy[2] (9 July 1808)
Physical properties
Phase aláralíle
Liquid density at m.p. 2.08 g·cm−3
Melting point 2349 K, 2076 °C, 3769 °F
Boiling point 4200 K, 3927 °C, 7101 °F
Heat of fusion 50.2 kJ·mol−1
Heat of vaporization 480 kJ·mol−1
Molar heat capacity 11.087 J·mol−1·K−1
Vapor pressure
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[3]
(mildly acidic oxide)
Electronegativity 2.04 (Pauling scale)
Ionization energies
(more)
1st: 800.6 kJ·mol−1
2nd: 2427.1 kJ·mol−1
3rd: 3659.7 kJ·mol−1
Atomic radius 90 pm
Covalent radius 84±3 pm
Van der Waals radius 192 pm
Miscellanea
Crystal structure rhombohedral
Bórọ̀nù has a rhombohedral crystal structure
Magnetic ordering diamagnetic[4]
Electrical resistivity (20 °C) ~106 Ω·m
Thermal conductivity 27.4 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 number 7440-42-8
Àwọn ísótòpù dídúró jùlọ
Main article: Àwọn ísótòpù bórọ̀nù
iso NA half-life DM DE (MeV) DP
10B 19.9(7)%* 10B is stable with 5 neutrons[6]
11B 80.1(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]
· r

Bórọ̀nù ni ẹ́límẹ̀ntì kẹ́míkà kan tó ní àmì-ìdámọ̀ B àti nọ́mbà átọ̀mù 5. Nítorípé bórọ̀nù jẹ́ dídá pátápátá pẹ̀lu ìtúká ìrànká kọ́smíkì tí kò sì jẹ́ pẹ̀lù núkléùkíkódájọpọ̀ oníràwọ̀,[8] kò fi bẹ́ẹ̀ pọ̀ ní inú sístẹ́mù òrùn àti nínú ìgbẹ́lẹ̀ Ayé. Bórọ̀nù wọ́jọ ní Ayé pẹ̀lu ìtúsómi àwọn àdàpọ̀ rẹ̀ tí wọ́n wọ́pọ̀, èyun ùn àwọn àlùmọ́nì bóràtì. Àwọn wọ̀nyí únjẹ́ wíwà láti inú ilẹ̀ ní ilé-iṣẹ́ gẹ́gẹ́bí ìṣágbẹ, bíi bóráksì àti kẹ́rnítì.

Bórọ̀nú, tó jẹ́ títòpọ̀ mọ́ ẹgbẹ́ mẹ́tálọ́ìdì, tí kò darapọ̀ bíi kẹ́míkà kò sí ní Ilé-Ayé. Ní ilé-iṣẹ́, ó ṣòro látí dá bórọ̀nù ògidì nítorípé oúndá èròjà míràn tí wọ́n ní kárbọ́nù tàbí àwọn ẹ́límẹ̀ntí míràn díẹ̀ nínú. Orísi àwọn àllótrópù bórọ̀nù lówà: bórọ̀nù amorphous boron is a brown powder and crystalline boron is black, extremely hard (about 9.5 on the Mohs scale), and a poor conductor at room temperature. Elemental boron is used as a dopant in the semiconductor industry.

Itokasi[àtúnṣe | àtúnṣe àmìọ̀rọ̀]

  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. Bibcode 1995JMoSp.170...82Z. doi:10.1006/jmsp.1995.1058. 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 0849304814. 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. http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl. 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. doi:10.1007/BF02165219. 
  8. "Q & A: Where does the element Boron come from?". physics.illinois.edu. http://van.physics.illinois.edu/qa/listing.php?id=17594. Retrieved 2011-12-04.