Silicon
Metalloid element belonging to group 14 of the periodic table. It is the second most abundant element in the Earth's crust, making up 25.7% of it by weight. Chemically less reactive than carbon. First identified by Lavoisier in 1787 and first isolated in 1823 by Berzelius.
Gallery
Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/silicon.php
Emission spectrum
Physical Propertiesmass · density · phase · crystal
Atomic Mass
28.0850Da
Density
2.3296g/cm³
Phase (STP)
Solid
Melting Point
1687.2K
Boiling Point
3538.2K
Molar Heat
0.7120J/(mol·K)
Crystal Structure
DIA
Lattice Constant
5.430Å
Atomic Radiiatomic · covalent · van der Waals
Atomic (Empirical)
110.00pm
Covalent
116.00pm
Van der Waals
210.00pm
Electronic Propertieselectronegativity · ionization · affinity
Electron Configuration
[Ne] 3s2 3p2
Electron Shells
2, 8, 4
Electronegativity
1.90Pauling
Electron Affinity
1.4kJ/mol
1st Ionization Energy
8.2kJ/mol
Oxidation States
-4, -3, -2, -1, 0, +1, +2, +3, +4
Orbital DiagramAufbau · Hund's rule · Pauli exclusion
Full: 1s2 2s2 2p6 3s2 3p2Short: [Ne] 3s2 3p2
Ionization Energies (14 known)
Emission Spectrumvisible range · characteristic spectral lines
Abundanceby mass
Log scale · ppm = parts per million by mass
Biological Role
Important for bone and connective tissue formation. Diatoms use it for their shells.
Discovery
Discovered By
Jöns Berzelius
Named By
—
Year
1824
Nuclear Data
Known Isotopes
24
Stable Isotopes
3
Stable Mass Numbers
28, 29, 30
Natural isotopic abundance (IUPAC recommended values)
Isotopes of Si24 known
| Nuclide | Z | N | Mass (AMU) | Half-life | Decay | Jπ | Abundance |
|---|---|---|---|---|---|---|---|
| 22Si | 14 | 8 | 22.036114 | 28.7 ms | β⁺ (1%), β⁺p (0.62%), 2p (0.006999999999999999%) | 0+ | — |
| 23Si | 14 | 9 | 23.025711 | 42.3 ms | β⁺ (1%), β⁺p (0.88%), 2p (0.036000000000000004%) | 3/2+ | — |
| 24Si | 14 | 10 | 24.011535 | 143 ms | β⁺ (1%), β⁺p (0.345%) | 0+ | — |
| 28Sistable | 14 | 14 | 27.976927 | Stable | stable (1%) | 0+ | 9225.4500% |
| 29Sistable | 14 | 15 | 28.976495 | Stable | stable (1%) | 1/2+ | 467.2000% |
| 30Sistable | 14 | 16 | 29.973770 | Stable | stable (1%) | 0+ | 307.3500% |
| 43Si | 14 | 29 | 43.026119 | Unknown | β⁻, β⁻n, 2n | 3/2- | — |
| 44Si | 14 | 30 | 44.031466 | Unknown | β⁻, β⁻n, 2n | 0+ | — |
| 45Si | 14 | 31 | 45.039818 | Unknown | β⁻, β⁻n, 2n | 3/2- | — |