Element 14 · Metalloid
Silicon (Si) — Element 14
Latin silex — flint
Silicon (Si) is a metalloid in Period 3, Group 14 of the periodic table with atomic number 14, standard atomic weight 28.085 u, and ground-state electron configuration [Ne] 3s² 3p². At standard temperature and pressure it is classified as a solid with 4 valence electrons and common oxidation states +4, -4.
Semiconductors, glass, concrete
What are the atomic properties and physical constants of Silicon?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 14
- Standard atomic mass
- 28.085 u
- Chemical family
- Metalloid
- Ground-state configuration
- [Ne] 3s² 3p²
- Electrons per shell
- 2, 8, 4
- Valence electrons
- 4
- Common ion charges / oxidation states
- +4, -4
- Phase at STP
- Solid
- Pauling electronegativity
- 1.90 Pauling
- First ionization energy
- 786 kJ/mol
- Atomic radius
- 111 pm
- Melting point
- 1,414 °C
- Boiling point
- 3,265 °C
- Discovery year
- 1824
- Table coordinate
- Period 3, Group 14
- Radioactivity
- Has stable isotope(s)
How are electrons arranged across Silicon’s shells?
A neutral Silicon atom contains 14 electrons distributed across 3 occupied principal energy shells ([Ne] 3s² 3p²). The table below compares Silicon’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Si | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 4 e⁻ | 18 e⁻ |
Frequently Asked Questions about Silicon (Si)
What is the atomic mass and atomic number of Silicon (Si)?
Silicon (Si) has atomic number Z = 14 (14 protons in its nucleus) and an IUPAC standard atomic weight of 28.085 u. It sits in Period 3, Group 14 and is classified as a metalloid.
What is the ground-state electron configuration of Silicon?
The neutral ground-state electron configuration of Silicon (Z = 14) is [Ne] 3s² 3p². Across its 3 occupied principal shells (n = 1 to n = 3), the electrons per shell are 2, 8, 4, with 4 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Silicon?
Silicon commonly forms +4, -4 oxidation states or ion charges in compounds. Its Pauling electronegativity is 1.90 and its first ionization energy is 786 kJ/mol.
When was Silicon discovered and what is it used for?
Silicon was discovered in 1824 (Latin silex — flint). Semiconductors, glass, concrete
How does Silicon compare to neighboring elements?
Other metalloid elements: