Silicon (Si)
Silicon (Si) is element 14, a metalloid. Atomic mass 28.085, configuration [Ne] 3s² 3p². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 14 |
|---|---|
| Symbol | Si |
| Standard atomic weight | [28.084,28.086] |
| Category | Metalloid |
| Group | 14 |
| Period | 3 |
| State at room temperature | Solid |
| Electron configuration | [Ne] 3s² 3p² |
| Valence electrons | 4 |
| Common oxidation states | -4, +4 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.9 |
| First ionization energy | 787 kJ/mol |
| Electron affinity | 134.1 kJ/mol |
| Atomic radius | 111 pm |
| Density | 2.33 g/cm³ |
| Melting point | 1415°C |
| Boiling point | 3265°C |
| Specific heat | 0.712 J/(g·°C) |
Natural isotopes
- Si-28: Stable
- Si-29: Stable
- Si-30: Stable
Common uses
- Electronics
- Glass/Concrete (as Silicates)
- Silicones
Where it matters
- The Digital Age (Semiconductors/Microchips)
- Solar energy (Photovoltaics)
Hazards
- Silicosis (chronic dust inhalation)
History
| Discovered | 1824 |
|---|---|
| Discovered by | Jöns Jakob Berzelius |
| Name | Thomas Thomson |