1428.086SiSilicon
Silicon (Si) — element 14metalloid · group 14, period 3
Silicon is a chemical element with the symbol Si and atomic number 14. It is a metalloid in group 14, period 3 of the periodic table (the p-block), with a standard atomic mass of 28.086 u. At room temperature (25 °C) silicon is a solid.
💡 Known for: The backbone of computer chips and solar cells, and the second most abundant element in Earth's crust.
# Silicon properties
| Symbol | Si |
|---|---|
| Atomic number | 14 |
| Atomic mass | 28.086 u |
| Category | metalloid |
| Group | 14 |
| Period | 3 |
| Block | p-block |
| Electron configuration | [Ne] 3s² 3p² |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p² |
| Electrons per shell | 2, 8, 4 |
| Protons / electrons | 14 / 14 |
| State at 25 °C | solid |
| Melting point | 1687 K (1413.8 °C, 2576.9 °F) |
| Boiling point | 3538 K (3264.8 °C, 5908.7 °F) |
| Density | 2.33 g/cm³ |
| Electronegativity (Pauling) | 1.9 |
| First ionization energy | 8.152 eV |
| Atomic radius | 111 pm |
| Discovered | 1824 |
# Electron configuration of silicon
The electron configuration of silicon is [Ne] 3s² 3p², written out in full as 1s² 2s² 2p⁶ 3s² 3p². Its 14 electrons fill 3 shells as 2, 8, 4, so the outermost shell holds 4 electrons. As a group 14 element, silicon has 4 valence electrons.
# Related elements
AlAluminiumprevious elementPPhosphorusnext elementCCarbongroup 14GeGermaniumgroup 14SnTingroup 14PbLeadgroup 14FlFleroviumgroup 14BBoronmetalloidAsArsenicmetalloidSbAntimonymetalloidTeTelluriummetalloid
# Silicon FAQ
What is the atomic number of silicon?
The atomic number of silicon is 14: every silicon atom has 14 protons in its nucleus. Its symbol is Si.
What is the atomic mass of silicon?
The standard atomic mass of silicon is 28.086 u.
What is the electron configuration of silicon?
Silicon's electron configuration is [Ne] 3s² 3p² (1s² 2s² 2p⁶ 3s² 3p²), with 2, 8, 4 electrons per shell.
Is silicon a metal?
No. Silicon is a metalloid, with properties between those of metals and nonmetals.
What is the melting point of silicon?
Silicon melts at 1687 K (1413.8 °C, 2576.9 °F) and boils at 3538 K (3264.8 °C, 5908.7 °F).
What is silicon used for / known for?
The backbone of computer chips and solar cells, and the second most abundant element in Earth's crust.