SILICIO

Introducción

Número Atómico: 14
Grupo: 14 or IV A
Peso Atómico: 28.0855
Periodo: 3
Número CAS: 7440-21-3

Clasificación

Anfígeno
Halógeno
Gases nobles
Lantánido
Actínido
Tierras Raras
Platino Metal Grupo
Transuránicos
No Isótopos Estables
Sólido
Líquido
Gas
Sólido (Predicción)

Descripción

Davy in 1800 thought silica to be a compound and not an element; later in 1811, Gay Lussac and Thenard probably prepared impure amorphous silicon by heating potassium with silicon tetrafluoride. Berzelius, generally credited with the discovery, in 1824 succeeded in preparing amorphous silicon by the same general method as used earlier, but he purified the product by removing the fluosilicates by repeated washings. Deville in 1854 first prepared crystalline silicon, the second allotropic form of the element. Silicon is present in the sun and stars and is a principal component of a class of meteorites known as “aerolites”. It is also a component of tektites, a natural glass of uncertain origin. Natural silicon contains three isotopes. Fourteen other radioactive isotopes are recognized. Silicon makes up 25.7% of the earth’s crust, by weight, and is the second most abundant element, being exceeded only by oxygen. Silicon is not found free in nature, but occurs chiefly as the oxide and as silicates. Sand, quartz, rock crystal, amethyst, agate, flint, jasper, and opal are some of the forms in which the oxide appears. Granite, hornblende, asbestos, feldspar, clay mica, etc. are but a few of the numerous silicate minerals. Silicon is prepared commercially by heating silica and carbon in an electric furnace, using carbon electrodes. Several other methods can be used for preparing the element. Amorphous silicon can be prepared as a brown powder, which can be easily melted or vaporized. Crystalline silicon has a metallic luster and grayish color. The Czochralski process is commonly used to produce single crystals of silicon used for solid-state or semiconductor devices. Hyperpure silicon can be prepared by the thermal decomposition of ultra-pure trichlorosilane in a hydrogen atmosphere, and by a vacuum float zone process. This product can be doped with boron, gallium, phosphorus, or arsenic to produce silicon for use in transistors, solar cells, rectifiers, and other solid-state devices which are used extensively in the electronics and space-age industries. Hydrogenated amorphous silicon has shown promise in producing economical cells for converting solar energy into electricity. Silicon is a relatively inert element, but it is attacked by halogens and dilute alkali. Most acids except hydrofluoric, do not affect it. Silicones are important products of silicon. They may be prepared by hydrolyzing a silicon organic chloride, such as dimethyl silicon chloride. Hydrolysis and condensation of various substituted chlorosilanes can be used to produce a very great number of polymeric products, or silicones, ranging from liquids to hard, glasslike solids with many useful properties. Elemental silicon transmits more than 95% of all wavelengths of infrared, from 1.3 to 6.7 mm. Silicon is one of man’s most useful elements. In the form of sand and clay it is used to make concrete and brick; it is a useful refractory material for high-temperature work, and in the form of silicates it is used in making enamels, pottery, etc. Silica, as sand, is a principal ingredient of glass, one of the most inexpensive of materials with excellent mechanical, optical, thermal, and electrical properties. Glass can be made in a very great variety of shapes, and is used as containers, window glass, insulators, and thousands of other uses. Silicon tetrachloride can be used to iridize glass. Silicon is important in plant and animal life. Diatoms in both fresh and salt water extract silica from the water to build up their cell walls. Silica is present in ashes of plants and in the human skeleton. Silicon is an important ingredient in steel; silicon carbide is one of the most important abrasives and has been used in lasers to produce coherent light of 4560 Å. Regular grade silicon (99.5%) costs about $140/kg. Silicon 99.96% pure costs about $250/kg; hyperpure silicon may cost as much as $400/kg. Miners, stonecutters, and other engaged in work where siliceous dust is breathed in large quantities often develop a serious lung disease known as silicosis. 1

Usos/Funciones

•its major use is in semiconductors for electronic devices" 2
•bone and connective tissue" 3
•Pure silicon is used in solar cells to collect energy from the sun...Elemental silicon is used to make silicone polymers. Its semiconducting properties are used in transistors and solar cells." 4
•used in electronic devices, while silicon in combination with oxygen as silica and silicates finds application in concrete, bricks, pottery, enamels, glasses, optical fibers for telecommunications, and refractory (high-temperature resistant) materials." 5
•Commercial-grade silicon is about 98% pure and is used in various metal alloys.

Silicon is the basic material of the solid-state electronics industry. Television receivers, microcomputers, and other electronic equipment so common today employ miniature circuits built on silicon chips. For this purpose, extremely pure silicon is required (containing about 1 impurity atom in 1012 silicon atoms).

Silicon is used in solid-state electronics devices because of its properties as a semiconductor, a material whose conductivity is intermediate between that of an insulator and a metal. Pure silicon at normal temperatures is essentially a nonconductor. Each of the atoms in silicon is bonded to four other silicon atoms through localized covalent bonds. Because the electrons in these bonds do not move over large distances, there are no free electronsto conduct an electric current. The addition of small quantities of certain substances to pure silicon, however, greatly enhances its conductivity and makes possible the construction of electronic devices. This controlled addition of impurities is called doping.

Consider what happens when we dope pure silicon with phosphorus, an element having five instead of the four valence electrons of silicon. A few of the silicon atoms in the structure are replaced by phosphorus atoms. Because each phosphorus atom has five valence electrons, one electron is left over after four bonds are formed to silicon atoms. The extra electron is free to conduct an electric current, and the phosphorus-doped silicon becomes a conductor. It is called an n-type semiconductor, because the current is carried by negative charges (electrons).

By doping silicon with an element having three valence electrons, the conductivity is also very much enhanced. Consider what happens when silicon is doped with boron. Some of the silicon atoms in the solid are replaced by boron atoms; but because each boron atom has only three valence electrons, one of the four bonds to each boron atom has only one electron in it. We can think if this as a vacancy or "hole" in the bonding orbital. An electron from a neighboring atomcan move in to occupy this hole. Then a hole would exist on the neighboring atom, and an electron from another atom can move into it. As a result of this movement, boron-doped silicon is an electrical conductor. Because a hole is an absence of an electron, it is essentially a positive charge. Boron-doped silicon is called a p-type semiconductor, because the charge is carried by positive holes. The semiconductor behavior of doped silicon also can be explained in molecular orbital terms." 6

Magnitudes Físicas

Punto de Fusión:7*  1414 °C = 1687.15 K = 2577.2 °F
Punto de Ebullición:7* 3265 °C = 3538.15 K = 5909 °F
Punto de Sublimación:7 
Punto Triple:7 
Punto Crítico:7 
Densidad:8  2.3290 g/cm3

* - at 1 atm

Configuración Electrónica

Configuración Electrónica: [Ne] 3s2 3p2
Bloque: p
Nivel Más Alto de Energía Ocupados: 3
Electrones de Valencia: 4

Números Cuánticos:

n = 3
ℓ = 1
m = 0
ms = +½

Enlace Químico

Electronegatividad (Escala de Pauling):9 1.90
Electropositivity (Escala de Pauling): 2.1
Afinidad Electrónica:10 1.389521 eV
Estados de Oxidación: ±4
Función de Trabajo:11 4.85 eV = 7.7697E-19 J

Energía de Ionización   eV 12  kJ/mol  
1 8.15169    786.5
2 16.34585    1577.1
3 33.49302    3231.6
4 45.14181    4355.5
Energía de Ionización   eV 12  kJ/mol  
4 45.14181    4355.5
5 166.767    16090.6
6 205.27    19805.5
7 246.5    23783.6
8 303.54    29287.2
9 351.12    33877.9
Energía de Ionización   eV 12  kJ/mol  
10 401.37    38726.3
11 476.36    45961.7
12 523.42    50502.3
13 2437.63    235195.5
14 2673.182    257922.8

Termoquímica

Capacidad Calorífica: 0.705 J/g°C 13 = 19.800 J/mol°C = 0.168 cal/g°C = 4.732 cal/mol°C
Conductividad Térmica: 148 (W/m)/K, 27ºC 14
Entalpía de Fusión: 50.55 kJ/mol 15 = 1799.9 J/g
Entalpía de Vaporización: 384.22 kJ/mol 16 = 13680.4 J/g
Estado de Agregación de la Materia Entalpía de Formación (ΔHf°)17 Entropía (S°)17 Energía Libre de Gibbs (ΔGf°)17
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 4.50 18.828 0 0
(g) 108.9 455.6376 40.12 167.86208 98.3 411.2872

Isótopos

Nucleido Masa 18 Periodo de Semidesintegración 18 Espín 18 Energía de enlace nuclear
22Si 22.03453(22)# 29(2) ms 0+ 130.35 MeV
23Si 23.02552(21)# 42.3(4) ms 3/2+# 146.81 MeV
24Si 24.011546(21) 140(8) ms 0+ 167.93 MeV
25Si 25.004106(11) 220(3) ms 5/2+ 182.53 MeV
26Si 25.992330(3) 2.234(13) s 0+ 201.79 MeV
27Si 26.98670491(16) 4.16(2) s 5/2+ 215.46 MeV
28Si 27.9769265325(19) ESTABLE 0+ 232.85 MeV
29Si 28.976494700(22) ESTABLE 1/2+ 240.93 MeV
30Si 29.97377017(3) ESTABLE 0+ 251.81 MeV
31Si 30.97536323(4) 157.3(3) min 3/2+ 258.02 MeV
32Si 31.97414808(5) 132(13) a 0+ 267.03 MeV
33Si 32.978000(17) 6.18(18) s (3/2+) 271.38 MeV
34Si 33.978576(15) 2.77(20) s 0+ 279.46 MeV
35Si 34.98458(4) 780(120) ms 7/2-# 281.95 MeV
36Si 35.98660(13) 0.45(6) s 0+ 288.17 MeV
37Si 36.99294(18) 90(60) ms (7/2-)# 290.66 MeV
38Si 37.99563(15) 90# ms [>1 µs] 0+ 295.94 MeV
39Si 39.00207(36) 47.5(20) ms 7/2-# 297.50 MeV
40Si 40.00587(60) 33.0(10) ms 0+ 302.78 MeV
41Si 41.01456(198) 20.0(25) ms 7/2-# 302.48 MeV
42Si 42.01979(54)# 13(4) ms 0+ 305.90 MeV
43Si 43.02866(75)# 15# ms [>260 ns] 3/2-# 305.59 MeV
44Si 44.03526(86)# 10# ms 0+ 307.15 MeV
Los valores marcados con # no se derivan exclusivamente de datos experimentales, pero al menos en parte, de las tendencias sistemáticas. Tiradas con argumentos de asignación débiles están encerrados entre paréntesis. 18

Reacciones

Abundancia

Tierra - Fuente Compuestos: silicates 22
Tierra - Agua de mar: 2.2 mg/L 23
Tierra -  Corteza:  282000 mg/kg = 28.2% 23
Tierra -  :  21.6% 24
Tierra -  Total:  15.12% 25
Mercurio -  Total:  7.05% 25
Venus -  Total:  15.82% 25
Universo -  Total:  0.06% 24
Condritas - Total: 1.00×106 (relative to 106 atoms of Si) 26
Cuerpo Humano - Total: 0.026% 27

Compuestos

Precios





Información Sobre Seguridad


Ficha de Datos de Seguridad - ACI Alloys, Inc.

Idiomas

Afrikáans:   Silikon
Albanés:   Silicium
Armenio:   Սիլիցիում
Árabe:   سيليكون
Arumano:   Silitsiumu
Euskera:   Silizioa
Bosnio:   Silicij
Bretón:   Silisiom
Búlgaro:   Силиций
Bielorruso:   Крэмній
Catalán:   Silici
Chino:   硅
Córnico:   Sylycon
Croata:   Silicij
Checo:   Kremík
Danés:   Silicium
Neerlandés:   Silicium
Esperanto:   Silicio
Estonio:   Räni
Feroés:   Silicium
Finés:   Pii
Francés:   Silicium
Friulano: Silici
Frisio:   Silisium
Gallego:   Silicio
Georgiano:   სიცილიუმი
Alemán:   Silizium
Griego:   Πυριτιο
Hebreo:   צורן
Húngaro:   Szilícium
Islandés:   Kísill
Irlandés:   Sileacón
Italiano:   Silicio
Japonés:   ケイ素
Casubio:   Krzém
Kazajo:   Кремний
Coreano:   규소
Letónico:   Silicijs
Lituano:   Silicis
Luxemburgués:   Silizium
Macedonio:   Силициум
Malayo:   Silikon
Maltés:   Silikon
Manés:   Shillagon
Moksha:   Атаем
Mongol:   Цахиур
Noruego:   Silisium
Occitano:   Silici
Osetio:   Кремний
Polaco:   Krzem
Portugués:   Silício
Ruso:   Кремний
Gaélico Escocés:   Sileacon
Serbio:   Силициjум
Eslovaco:   Kremík
Español:   Silicio
:   Silicijan
Suajili:   Silikoni
Sueco:   Kisel
Tayiko:   Silitziy
Tailandés:   ซิลิคอน
Turco:   Silisyum
Ucraniano:   Кремній
Uzbeko:   Кремний
Vietnamita:   Silic
Galés:   Sílicon

Véase También

Enlaces Externos:

Fuentes

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(2) - Zumdahl, Steven S. Chemistry, 4th ed.; Houghton Mifflin: Boston, 1997; p 889.
(3) - Whitten, Kenneth W., Davis, Raymond E., and Peck, M. Larry. General Chemistry 6th ed.; Saunders College Publishing: Orlando, FL, 2000; p 926.
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(5) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 6.
(6) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 392, 394.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
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(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(11) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(12) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
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(20) - Kotz, John C. and Treichel, Paul. Chemistry & Chemical Reactivity 4th ed.; Thomson Brooks/Cole: Belmont, CA, 1999; p 158.
(21) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 379.
(22) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
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(24) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 962.
(25) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
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