Electron Configuration of Sodium (Na)
Sodium (Na, Z = 11) has the electron configuration [Ne] 3s^1, filling 3 shells with 2, 8, 1 electrons.
Teachers call it "one fact, fully handled" — exactly what this page does for Sodium. The answer sits at the top in bold; scroll for the working, the shell-by-shell breakdown and the two questions students ask most. Need the whole picture instead — history, characteristics, uses, exam questions? The full Sodium page is one click away.
Sodium: every subshell, one by one
Start from 1s and follow the running total: this is exactly how examiners expect you to build Sodium's configuration on paper.
| Subshell | Electrons | Total so far |
|---|---|---|
| [Ne] | 0 | 10 |
| 3s | 1 | 11 |
Electrons per shell (K, L, M…)
Grouped by principal quantum number instead of subshell, Sodium carries 2 in shell 1, 8 in shell 2, 1 in shell 3. The outermost shell holds 1 electron — the ones that do all the bonding.
How to derive it yourself
Follow the aufbau order (1s → 2s → 2p → 3s → 3p → 4s → 3d → …), pouring 11 electrons into orbitals of capacity 2 (s), 6 (p), 10 (d) and 14 (f) until none remain. Write the filled inner shells as the nearest noble-gas core — for Sodium that gives [Ne] 3s^1.
Students also ask
How many electron shells does Sodium have?
Sodium is in period 3, so its electrons occupy 3 shells, holding 2, 8, 1 electrons respectively.
How many valence electrons does Sodium have?
Its outermost shell holds 1 electron, so Sodium has 1 valence electron that take part in bonding.
What is the noble-gas shorthand for Sodium?
The shorthand form is exactly [Ne] 3s^1.