Silicon (Si)
Metalloid · p-block · period 3 · group 14
Hard, brittle, blue-grey crystalline metalloid with a metallic sheen.
Silicon (symbol Si) is chemical element number 14, a metalloid in group 14, period 3 of the periodic table. Its standard atomic weight is 28.085 and its electron configuration is [Ne] 3s2 3p2. At room temperature it is a solid. Second most abundant element in the Earth's crust, after oxygen.
Properties
| Atomic number | 14 |
|---|---|
| Atomic mass | 28.085 |
| Category | Metalloid |
| Block | p-block |
| Group · Period | 14 · 3 |
| Electron configuration | [Ne] 3s2 3p2 |
| Electrons per shell | 2, 8, 4 |
| State at 25 °C | solid |
| Melting point | 1687 K |
| Boiling point | 3538 K |
| Density | 2.329 g/cm³ |
| Electronegativity (Pauling) | 1.9 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1824 · Jöns Jacob Berzelius |
Key facts about Silicon
- Second most abundant element in the Earth's crust, after oxygen.
- The semiconductor that the entire computer industry is built on.
- Sand, quartz and glass are all mostly silicon dioxide.
- Ultra-pure silicon crystals are grown as huge cylindrical 'boules'.
What Silicon is used for
Computer chips and solar cells, glass and ceramics, silicone rubbers and sealants, steel alloying.
Where it sits in the periodic table
Silicon is in group 14, period 3, of the p-block. Its electron configuration [Ne] 3s2 3p2 means its outermost shell holds 4 electrons, which is what places it here and explains much of its chemistry. See Silicon on the interactive table →
Silicon — frequently asked questions
What is Silicon used for?
Computer chips and solar cells, glass and ceramics, silicone rubbers and sealants, steel alloying.
Is Silicon radioactive?
No. Silicon has at least one stable isotope and is not radioactive.
What is the electron configuration of Silicon?
Silicon has the electron configuration [Ne] 3s2 3p2, which is 2, 8, 4 electrons per shell.
What group and period is Silicon in?
Silicon is in group 14, period 3, in the p-block. Its outer shell holds 4 electrons.
Who discovered Silicon?
Silicon was discovered in 1824 by Jöns Jacob Berzelius.