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14Si28.085
Silicon
MetalloidSilicon is a chemical element with symbol Si and atomic number 14. It is a tetravalent metalloid, more reactive than germanium, the metalloid directly below it in the table. Controversy about silicon's character dates to its discovery.
Phase: SolidAppearance: crystalline, reflective with bluish-tinged faces
2, 8, 4
Physical Properties
Atomic Mass28.085 u
Density2.329 g/cm³
Melting Point1687 K
Boiling Point3538 K
Molar Heat19.789 J/(mol·K)
Period3
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p2
Semantic Config[Ne] 3s2 3p2
Shells2, 8, 4
Electron Affinity134.0684 kJ/mol
Electronegativity1.9
Ionization Energies
IE1: 786.5 kJ/molIE2: 1577.1 kJ/molIE3: 3231.6 kJ/molIE4: 4355.5 kJ/molIE5: 16091 kJ/molIE6: 19805 kJ/molIE7: 23780 kJ/molIE8: 29287 kJ/molIE9: 33878 kJ/molIE10: 38726 kJ/molIE11: 45962 kJ/molIE12: 50502 kJ/molIE13: 235196 kJ/molIE14: 257923 kJ/mol
Discovery