Technical data for Silicon

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
Heat of Fusion50.2 kJ/mol
Heat of Vaporization359 kJ/mol
Heat of Combustion-9055 J/(kg K)
Specific Heat710 J/(kg K)[note]
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)

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blockp
Group14
Period3
Electron Configuration[Ne]3s23p2
ColorGray
Discovery
1824 in Sweden
Gas phaseN/A
CAS NumberCAS7440-21-3

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
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.