???? : Infobox boron

Boron, ₀₀B
	boron (β-rhombohedral)
Boron
Pronunciation	/ ? b ?ːr ? n / ( BOHR -on )
????????????	α-, β-rhombohedral, β-tetragonal (and more )
Appearance	black-brown
Boron ??????????????????
	beryllium ← boron → carbon
????????	group 13 (boron group)
??????	period 2
????????	p-block
????????? ????????	[ He ] 2s 2 2p 1
Electrons per shell	2, 3
Physical properties
Phase at STP	solid
??????????	2349 K (2076 °C, 3769 °F)
??????????	4200 K (3927 °C, 7101 °F)
Density when liquid (at m.p. )	2.08 g/cm 3
????????? ???????	50.2 kJ/mol
Heat of vaporization	508 kJ/mol
Molar heat capacity	11.087 J/(mol·K)
Atomic properties
Oxidation states	?5, ?1, +1, +2, +3 (a mildly acidic oxide)
Electronegativity	Pauling scale: 2.04
???????? ????	1st: 800.6 kJ/mol ; 2nd: 2427.1 kJ/mol ; 3rd: 3659.7 kJ/mol ; ( more ) ;
???????? ???	empirical: 90 pm
????????? ???????	84±3 pm
Van der Waals radius	192 pm
	Spectral lines of boron
Other properties
Natural occurrence	primordial
?????????? ???	rhombohedral
Speed of sound thin rod	16,200 m/s (at 20 °C)
Thermal expansion	β form: 5?7 μm/(m?K) (at 25 °C)
????????	27.4 W/(m?K)
Electrical resistivity	~10 6 Ω?m (at 20 °C)
????????	diamagnetic
????????????	?6.7·10 ?6 cm 3 /mol
Mohs hardness	~9.5
??.?.??? ?????	7440-42-8
History
Discovery	Joseph Louis Gay-Lussac and Louis Jacques Thenard (30 June 1808)
First isolation	Humphry Davy (9 July 1808)
Isotopes of boron ?? • [{{fullurl:Template:{{{template}}}\|action=edit}} ?? ]
	Template:infobox boron isotopes does not exist
	??????: Boron ; view ; talk ; edit ; \| references

B · Boron
	^iso B E infobox E isobox	→ H ibox H
[[:Category:\|cat:B]] (0) cat:B-isotopes (0) Commons Wikidata: Wiktionary
indexes by PT (page) ? ??

Data sets read by {{Infobox element}}
Name and identifiers	view edit
Top image	view edit
image caption	view edit
image alt	view edit
Pronunciation	view edit
Category (enwiki)	view edit
Standard atomic weight	view edit
most stable isotope	view edit
Oxidation states	view edit
Spectral lines image	view edit

References

↑ Van Setten et al. 2007, pp. 2460?1
↑ 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 .
↑ Melanie Schroeder. "Eigenschaften von borreichen Boriden und Scandium-Aluminium-Oxid-Carbiden" (PDF) (in ??????). p. 139.
↑ 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.
↑ ^5.0 ^5.1 Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press . p. 4.127. ISBN 9781498754293 .
↑ Gay Lussac, J.L.; Thenard, L.J. (1808). "Sur la decomposition et la recomposition de l'acide boracique" . Annales de chimie . 68 : 169?174. {{ cite journal }}: Unknown parameter |lastauthoramp= ignored ( |name-list-style= suggested) ( help )
↑ 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 : 39?104. doi : 10.1098/rstl.1809.0005 .
↑ ^8.0 ^8.1 "Atomic Weights and Isotopic Compositions for All Elements" . National Institute of Standards and Technology . Retrieved 2008-09-21 .
↑ Szegedi, S.; Varadi, M.; Buczko, Cs. M.; Varnagy, 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 .

Five of these are named references . They may be cited in the containing article as

<ref name="v1" /> for the source Infrared Emission Spectroscopy of BF and AIF
<ref name="magnet" /> for the source from Handbook of Chemistry and Physics
<ref name="NISTic" /> for the source Atomic Weights and Isotopic Compositions for All Elements
<ref name="Lussac" /> for the source by Gay-Lussac
<ref name="Davy" /> for the source by Davy

????:??????/????

[1] Van Setten et al. 2007, pp. 2460?1

[v1-2] 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] Melanie Schroeder. "Eigenschaften von borreichen Boriden und Scandium-Aluminium-Oxid-Carbiden" (PDF) (in ??????). p. 139.

[4] 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.

[crc97-5] 5.0 ^5.1 Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press . p. 4.127. ISBN 9781498754293 .

[Lussac-6] Gay Lussac, J.L.; Thenard, L.J. (1808). "Sur la decomposition et la recomposition de l'acide boracique" . Annales de chimie . 68 : 169?174. {{ cite journal }}: Unknown parameter |lastauthoramp= ignored ( |name-list-style= suggested) ( help )

[Davy-7] 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 : 39?104. doi : 10.1098/rstl.1809.0005 .

[NISTic-8] 8.0 ^8.1 "Atomic Weights and Isotopic Compositions for All Elements" . National Institute of Standards and Technology . Retrieved 2008-09-21 .

[9] Szegedi, S.; Varadi, M.; Buczko, Cs. M.; Varnagy, 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 .

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