Silicon
Silicon is a chemical element. Its atomic number is 14 on the periodic table. Its symbol is Si. It is a hard, brittle crystalline solid. It is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table.
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| Silicon | ||||||
|---|---|---|---|---|---|---|
| Pronunciation | ||||||
| Allotropes | see Allotropes of silicon | |||||
| Appearance | crystalline, reflective with bluish-tinged faces | |||||
| Standard atomic weight Ar°(Si) | ||||||
| [28.084, 28.086][1] | ||||||
| Silicon in the periodic table | ||||||
| ||||||
| Group | group 14 (carbon group) | |||||
| Period | period 3 | |||||
| Block | p-block | |||||
| Electron configuration | [Ne] 3s2 3p2 | |||||
| Electrons per shell | 2, 8, 4 | |||||
| Physical properties | ||||||
| Phase at STP | solid | |||||
| Melting point | 1687 K (1414 °C, 2577 °F) | |||||
| Boiling point | 3538 K (3265 °C, 5909 °F) | |||||
| Density (near r.t.) | 2.3290 g/cm3 | |||||
| when liquid (at m.p.) | 2.57 g/cm3 | |||||
| Heat of fusion | 50.21 kJ/mol | |||||
| Heat of vaporization | 383 kJ/mol | |||||
| Molar heat capacity | 19.789 J/(mol·K) | |||||
| Vapor pressureTemplate:Center block | ||||||
| Atomic properties | ||||||
| Oxidation states | −4, −3, −2, −1, 0,[2] +1,[3] +2, +3, +4 (an amphoteric oxide) | |||||
| Electronegativity | Pauling scale: 1.90 | |||||
| Ionization energies |
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| Atomic radius | empirical: 111 pm | |||||
| Covalent radius | 111 pm | |||||
| Van der Waals radius | 210 pm | |||||
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| Other properties | ||||||
| Natural occurrence | primordial | |||||
| Crystal structure | face-centered diamond-cubic | |||||
| Speed of sound thin rod | 8433 m/s (at 20 °C) | |||||
| Thermal expansion | 2.6 µm/(m⋅K) (at 25 °C) | |||||
| Thermal conductivity | 149 W/(m⋅K) | |||||
| Electrical resistivity | 2.3×103 Ω⋅m (at 20 °C)[4] | |||||
| Band gap | 1.12 eV (at 300 K) | |||||
| Magnetic ordering | diamagnetic[5] | |||||
| Molar magnetic susceptibility | −3.9·10−6 cm3/mol (298 K)[6] | |||||
| Young's modulus | 130–188 GPa[7] | |||||
| Shear modulus | 51–80 GPa[7] | |||||
| Bulk modulus | 97.6 GPa[7] | |||||
| Poisson ratio | 0.064–0.28[7] | |||||
| Mohs hardness | 6.5 | |||||
| CAS Number | 7440-21-3 | |||||
| History | ||||||
| Naming | after Latin 'silex' or 'silicis', meaning flint | |||||
| Prediction | Antoine Lavoisier (1787) | |||||
| Discovery and first isolation | Jöns Jacob Berzelius[8][9] (1823) | |||||
| Named by | Thomas Thomson (1817) | |||||
| Isotopes of silicon | ||||||
Silicon looks like a metal, but cannot do everything that a metal can, like conduct electricity well. Silicon is used a lot in today's computers and nearly every other electronic device as well. Germanium can also be used in computers, but silicon is much easier to find.
For example, all of the sand found at the beach is made of small cubes of silicon dioxide also known as silica. Glass is made by heating sand hot enough until it melts.[10] Glass made from silicon can be made in different colours by adding colouring compounds. Many rocks and minerals are composed of compounds of silicon and oxygen called silicates.
Silicon in computers change
Silicon is a semiconductor, and much used in computers. A super-pure isotope of silicon, silicon-28, can now be made 40 times more pure than before. It is very important for the next big development in computers. This stores "qubits" in atoms of another element, like phosphorous, embedded in a tiny layer of ultra-pure silicon-28. These qubits can simultaneously encode a one and a zero, for incredibly fast and complex calculations.[11]
Related pages change
References change
- ↑ "Standard Atomic Weights: Silicon". CIAAW. 2009.
- ↑ "New Type of Zero-Valent Tin Compound". Chemistry Europe. 27 August 2016.
- ↑ Ram, R. S.; et al. (1998). "Fourier Transform Emission Spectroscopy of the A2D–X2P Transition of SiH and SiD" (PDF). J. Mol. Spectr. 190 (2): 341–352. doi:10.1006/jmsp.1998.7582. PMID 9668026.
- ↑ Eranna, Golla (2014). Crystal Growth and Evaluation of Silicon for VLSI and ULSI. CRC Press. p. 7. ISBN 978-1-4822-3281-3.
- ↑ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
- ↑ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
- ↑ 7.0 7.1 7.2 7.3 Hopcroft, Matthew A.; Nix, William D.; Kenny, Thomas W. (2010). "What is the Young's Modulus of Silicon?". Journal of Microelectromechanical Systems. 19 (2): 229. doi:10.1109/JMEMS.2009.2039697.
- ↑ Weeks, Mary Elvira (1932). "The discovery of the elements: XII. Other elements isolated with the aid of potassium and sodium: beryllium, boron, silicon, and aluminum". Journal of Chemical Education. 9 (8): 1386–1412. Bibcode:1932JChEd...9.1386W. doi:10.1021/ed009p1386.
- ↑ Voronkov, M. G. (2007). "Silicon era". Russian Journal of Applied Chemistry. 80 (12): 2190. doi:10.1134/S1070427207120397.
- ↑ "Glass Crusher Machines". www.qcr.co.uk. Retrieved 24 May 2016.
- ↑ Webb, Jonathan 2014. Purer-than-pure silicon solves problem for quantum tech. BBC News Science & Environment [1]