General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Silicon Symbol Si
atomic number 14 Atomic weight 28.0855
Density @ 293 K 2.33 g/cm3 Atomic volume 12.1 cm3/mol
Group Non-Metal, Carbon group discovered 1824


state (s, l, g) s
melting point 1683.2 K boiling point 3553 K
Heat of fusion 50.550 kJ/mol Heat of vaporization 384.220 kJ/mol
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1st ionization energy 786.4 kJ/mole electronegativity 1.9
2nd ionization energy 1577 kJ/mole electron affinity 133.6 kJ/mole
3rd ionization energy 3231.5 kJ/mole Specific heat 0.71 J/gK
heat atomization 452 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,4 electron configuration [Ne] 3s2 3p2
minimum oxidation number -4 maximum oxidation number 4
min. common oxidation no. -4 max. common oxidation no. 4
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Appearance & Characteristics

structure diamond color gray-black
uses comp chip,lubricant,glass toxicity
hardness 7 mohs characteristics semimetal


reaction with air mild, = SiO2 reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH mild, = silicates
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Other Forms

number of isotopes 3 hydride(s) SiH4 Si2H6 + more
oxide(s) SiO2 chloride(s) SiCl4 Si2Cl6 + more


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 117.6 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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thermal conductivity 149 J/m-sec-deg electrical conductivity 0.012 1/mohm-cm
polarizability 5.4 A^3


source Quartz (oxide) rel. abund. solar system 6.000 log
abundance earth's crust 5.5 log cost, pure 5.4 $/100g
cost, bulk 0.14 $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.