014Metalloid · Group 14 · Period 3
Silicon
Silicon (Si) is element 14, a metalloid in the p-block — group 14, period 3. It is a solid at room temperature with 3 electron shells (2, 8, 4) and an atomic mass of 28.085 u.
- Atomic mass
- 28.09 u
- Phase · STP
- solid
- Melting
- 1687 K · 1414 °C
- Boiling
- 3538 K · 3265 °C
- Electronegativity
- 1.9
- Density
- 2.329 g/cm³
Photograph — 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
The visible light Silicon emits when energised — its unique spectral fingerprint.
Identity
- Atomic number
- 14
- Standard atomic weight
- 28.09 u
- Category
- Metalloid
- Group
- 14
- Period
- 3
- Block
- p-block
- Oxidation states
- +4, +2, -4
Physical properties
- Melting point
- 1687 K · 1414 °C
- Boiling point
- 3538 K · 3265 °C
- Density
- 2.329 g/cm³
- Molar heat capacity
- 19.789 J/(mol·K)
- Atomic radius
- 210 pm
- Electron affinity
- 134.0684 kJ/mol
Atomic structure
14protons
14neutrons
14electrons
4valence e⁻
- Noble-gas notation
- [Ne] 3s2 3p2
- Full configuration
- 1s2 2s2 2p6 3s2 3p2
- Electrons per shell
- 2, 8, 4
Periodic trends
Where Silicon ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
786.51
1.6k2
3.2k3
4.4k4
16.1k5
19.8k6
23.8k7
29.3k8
33.9k9
38.7k10
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1854
- Discovered by
- Jöns Jacob Berzelius
- Named by
- Thomas Thomson (chemist)
- Appearance
- crystalline, reflective with bluish-tinged faces