Silicon (Si)
[Ne] 3s² 3p². 2 unpaired electrons, period 3, group 14, p block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
SiSilicon, Z = 14, 28.085 u
[Ne] 3s2 3p2
In full: 1s² 2s² 2p⁶ 3s² 3p²
- Blockp block
- Period3
- Group14
- Valence4
- Unpaired2
- MagneticPara
Last electron 3p
- n3shell
- l1p subshell
- m0orbital
- s+½spin up
Step by step
- Silicon has 14 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p².
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p².
- Replace the neon core with [Ne]: [Ne] 3s² 3p².
Silicon (Si): the numbers
| Atomic number | 14 |
|---|---|
| Atomic mass | 28.085 u |
| Period | 3 |
| Group | 14 |
| Block | p block |
| Valence electrons | 4 |
| Unpaired electrons | 2 |
| Magnetic | paramagnetic |
| Last electron | 3p: n = 3, l = 1, m = 0, s = +1/2 |
Silicon (Si): quick answers
What is the electronic configuration of silicon?
Silicon has 14 electrons: 1s² 2s² 2p⁶ 3s² 3p², or [Ne] 3s² 3p² in short.
How many unpaired electrons does silicon have?
Silicon has 2 unpaired electrons, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of silicon?
The last electron goes into 3p: n = 3, l = 1, m = 0, s = +1/2. Orbitals fill from m = −l up, spin +½ first.