Silicon (Si): electron configuration, atomic mass and facts
Silicon (Si) is element 14 of the periodic table, a metalloid in period 3, group 14. Its electron configuration is [Ne] 3s2 3p2, with electrons arranged in shells 2, 8, 4, and its standard atomic weight is 28.085 u.
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| Symbol | Si |
|---|---|
| Atomic number | 14 |
| Atomic mass | 28.085 u |
| Category | Metalloid |
| Group | 14 |
| Period | 3 |
| Block | p-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p2 |
| Noble-gas shorthand | [Ne] 3s2 3p2 |
| Electrons per shell | 2, 8, 4 |
| Outer-shell electrons | 4 |
| Electronegativity (Pauling) | 1.9 |
| State at 20 °C | solid |
Where is Silicon on the periodic table?
Silicon is in period 3, group 14, in the p-block. The period number matches its 3 electron shells, and the block names the subshell its last electrons fill. In the same group, Carbon sits directly above it and Germanium sits directly below it. Elements in one group have the same number of outer-shell electrons (4 here), which is why they react in similar ways.
How to work out the electron configuration of Silicon
Put 14 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p² (14). In shorthand, [Ne] stands for the 10 electrons of neon, giving [Ne] 3s² 3p².
How electronegative is Silicon?
Silicon has a Pauling electronegativity of 1.9, ranking 37 of the 100 elements with a known value (fluorine is highest at 3.98). That is in the middle of the range.
Frequently asked questions
What is the electron configuration of Silicon?
The electron configuration of Silicon (Si) is 1s2 2s2 2p6 3s2 3p2. In noble-gas shorthand it is written [Ne] 3s2 3p2.
How many electrons does Silicon have in each shell?
Silicon has 14 electrons arranged in shells as 2, 8, 4. It has 4 electrons in its outer shell.
What is the atomic mass of Silicon?
The standard atomic weight of Silicon is 28.085 u, so one mole of Silicon atoms has a mass of about 28.085 g.
Is Silicon a metal?
Silicon is a metalloid: its properties sit between those of metals and nonmetals.
Explore nearby elements
More metalloids: Boron, Germanium, Arsenic, Antimony, Tellurium. See all elements on the periodic table.