Silicon

Silicon Element Properties

p13
Al
Aluminium
p14
Si
Silicon
p15
P
Phosphorus
General
NameSilicon
SymbolSi
Number14
Group Number14
GroupNon-Metal, Carbon group
Blockp
Density2.33 g/cm3
Atomic Weight28.0855 g/mol
Atomic Volume12.1 cm3/mol
Discover1824


States
StateSolid
Melting Point1687 K
Boiling Point3538 K
Triple PointNil
Critical PointNil
Heat of Fusion50.21 kJ/mol
Heat of Vaporization359 kJ/mol


Energies
First Ionization Energy786.4 kJ/mole
Second Ionization Energy1577 kJ/mole
Third Ionization Energy3231.5 kJ/mole
Electronegativity1.9
Electron Affinity133.6 kJ/mole
Specific Heat0.71 J/gK
Heat Atomization452 kJ/mole atoms


Oxidation and Electrons
Shells2,8,4
Electron Configuration[Ne] 3s2 3p2
Minimum Oxidation Number-4
Maximum Oxidation Number4
Minimum Common Oxidation Number-4
Maximum Common Oxidation Number4


Appearance and Characteristics
Crystal StructureDiamond cubic
Characteristicssemimetal
Colorgray-black
Usescomp chip,lubricant,glass
Hardness7 mohs
ToxicityNone


Reactions
Reaction with Airmild, =>SiO2
Reaction with 6M HClNone
Reaction with 15M HNO3None
Reaction with 6M NaOHmild, =>silicates


Other Forms
Number of Isotopes3
HydrideSiH4 Si2H6 + more
OxideSiO2
ChlorideSiCl4 Si2Cl6 + more


Radius
Atomic Radius117.6 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity149 J/m-sec-deg
Electrical Conductivity0.012 1/mohm-cm
Polarizability5.4 A3


Abundance
SourceQuartz (oxide)
Relation Abundance Solar System6.000 log
Abundance Earth's Crust5.5 log


p13
Al
Aluminium
p14
Si
Silicon
p15
P
Phosphorus