Chemicool

Si

14

28.0855
Silicon
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
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

States
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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Energies
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

Reactions
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

Radius
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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Conductivity
thermal conductivity 149 J/m-sec-deg electrical conductivity 0.012 1/mohm-cm
polarizability 5.4 A^3

Abundance
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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