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Technical data for Silicon

Click any property name to see plots of that property for all the elements.

Overview
NameSilicon
SymbolSi
Atomic Number14
Atomic Weight28.0855
Density2.33 g/cm3
Melting Point1414 °C
Boiling Point2.9×103 °C

Thermal properties
PhaseSolid
Melting Point1414 °C
Boiling Point2.9×103 °C
Absolute Melting Point1687 K
Absolute Boiling Point3173 K
Critical PressureN/A
Critical TemperatureN/A
Heat of Fusion50.2 kJ/mol
Heat of Vaporization359 kJ/mol
Heat of Combustion-9055 J/(kg K)
Specific Heat710 J/(kg K)[note]
Adiabatic IndexN/A
Neel PointN/A
Thermal Conductivity150 W/(m K)
Thermal Expansion2.6×10-6 K-1

Bulk physical properties
Density2.33 g/cm3
Density (Liquid)2.57 g/cm3
Molar Volume0.000012054
Brinell HardnessN/A
Mohs Hardness6.5 MPa
Vickers HardnessN/A
Bulk Modulus100 GPa
Shear ModulusN/A
Young Modulus47 GPa
Poisson RatioN/A
Refractive IndexN/A
Speed of Sound2.2×103 m/s
Thermal Conductivity150 W/(m K)
Thermal Expansion2.6×10-6 K-1

Reactivity
Valence4
Electronegativity1.9
ElectronAffinity133.6 kJ/mol
Ionization Energies
786.5, 1577.1, 3231.6, 4355.5, 16091, 19805, 23780, 29287, 33878, 38726 kJ/mol

Health and Safety
Autoignition Point150 °C
FlashpointN/A
Heat of Combustion-9055 J/(kg K)
DOT Hazard Class4.1
DOT Numbers1346
EU NumberN/A
NFPA Fire Rating0
NFPA HazardsN/A
NFPA Health Rating1
NFPA Reactivity Rating0
RTECS NumberRTECSVW0400000
NFPA LabelNFPA Label

Classifications
Alternate NamesNone
Names of AllotropesNone
Blockp
Group14
Period3
Electron Configuration[Ne]3s23p2
ColorGray
Discovery
1824 in Sweden
Gas phaseN/A
CAS NumberCAS7440-21-3
CID NumberCID5461123
Gmelin NumberN/A
NSC NumberN/A
RTECS NumberRTECSVW0400000

Electrical properties
Electrical TypeSemiconductor
Electrical Conductivity1×103 S/m
Resistivity0.001 m Ω
Superconducting PointN/A

Magnetic properties
Magnetic TypeDiamagnetic
Curie PointN/A
Mass Magnetic Susceptibility-1.6×10-9
Molar Magnetic Susceptibility-4.49×10-11
Volume Magnetic Susceptibility-3.73×10-6

Abundances
% in Universe0.07%
% in Sun0.09%
% in Meteorites14%
% in Earth's Crust27%
% in Oceans0.0001%
% in Humans0.026%

Atomic dimensions and structure
Atomic Radius111 pm
Covalent Radius111 pm
Van der Waals Radius210 pm
Crystal StructureTetrahedral Packing
Lattice Angles
π/2, π/2, π/2
Lattice Constants
543.09, 543.09, 543.09 pm
Space Group NameFd_ 3m
Space Group Number227

Nuclear Properties
Half-LifeStable
LifetimeStable
Decay ModeN/A
Quantum Numbers3P0
Neutron Cross Section171
Neutron Mass Absorption0.0002
Known Isotopes
22Si, 23Si, 24Si, 25Si, 26Si, 27Si, 28Si, 29Si, 30Si, 31Si, 32Si, 33Si, 34Si, 35Si, 36Si, 37Si, 38Si, 39Si, 40Si, 41Si, 42Si, 43Si, 44Si
Stable Isotopes
28Si, 29Si, 30Si
Isotopic Abundances
28Si92.2297%
29Si4.6832%
30Si3.0872%


Notes on the properties of Silicon:

Specific Heat: Value given for solid phase.

Up to date, curated data provided by
Mathematica's ElementData function from Wolfram Research, Inc.

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