Boron
Lát'ọwọ́ Wikipedia, ìwé ìmọ̀ ọ̀fẹ́
|
|
| Ìfarahàn |
black/brown
 |
| Àwọn ìní àníkárí |
| Orúkọ, àmì-ìdámọ̀, nọ́mbà |
boron, B, 5 |
| Ẹ̀ka apilẹ̀sẹ̀ |
metalloid |
| Àdìpọ̀, ìgbà, block |
13, 2, p |
| Ìwúwo átọ́mù |
10.811(7) g·mol−1 |
| Ìtòjọ ẹ̀lẹ́ktrónì |
[He] 2s2 2p1 |
| Àwọn ẹ̀lẹ́ktrónì lórí ọ̀nà kan |
2, 3 (Image) |
| Àwọn ìní aláfójúrí |
| Phase |
solid |
| Liquid density at m.p. |
2.08 g·cm−3 |
| ojúàmì ìyọ́ |
2349 K, 2076 °C, 3769 °F |
| ajúàmì ìhó |
4200 K, 3927 °C, 7101 °F |
| Heat of fusion |
50.2 kJ·mol−1 |
| Heat of vaporization |
480 kJ·mol−1 |
| Specific heat capacity |
(25 °C) 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 |
4,[1] 3, 2, 1[2]
(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 |
| Magnetic ordering |
diamagnetic[3] |
| Electrical resistivity |
(20 °C) ~106Ω·m |
| Thermal conductivity |
(300 K) 27.4 W·m−1·K−1 |
| Thermal expansion |
(25 °C) (ß form) 5–7 [4] µm·m−1·K−1 |
| Speed of sound (thin rod) |
(20 °C) 16,200 m/s |
| Mohs hardness |
~9.5 |
| CAS registry number |
7440-42-8 |
|
|
- ↑ W.T.M.L. Fernando, L.C. O'Brien, P.F. Bernath (1990). "Fourier Transform Spectroscopy: B4Σ−−X4Σ−". J. Chem. Phys. 93: 8482. doi:10.1063/1.459287. http://bernath.uwaterloo.ca/media/78.pdf.
- ↑ K.Q. Zhang, B.Guo, V. Braun, M. Dulick, P.F. Bernath (1995). "Infrared Emission Spectroscopy of BF and AIF". J. Molecular Spectroscopy 170: 82. doi:10.1006/jmsp.1995.1058. http://bernath.uwaterloo.ca/media/125.pdf.
- ↑ editor-in-chief, David R. Lide. (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.
- ↑ C. E. Holcombe Jr., D. D. Smith, J. D. Lorc, W. K. Duerlesen, and D. A. Carpenter (1973). "Physical-Chemical Properties of beta-Rhombohedral Boron". High Temp. Sci. 5: 349.
