Lanthanide

Electron Configuration of Samarium (Sm)

Quick answer

Samarium (Sm, Z = 62) has the electron configuration [Xe] 4f^6 6s^2, filling 6 shells with 2, 8, 18, 24, 8, 2 electrons.

Teachers call it "one fact, fully handled" — exactly what this page does for Samarium. 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 Samarium page is one click away.

Samarium: every subshell, one by one

Start from 1s and follow the running total: this is exactly how examiners expect you to build Samarium's configuration on paper.

SubshellElectronsTotal so far
[Xe]054
4f660
6s262

Electrons per shell (K, L, M…)

Grouped by principal quantum number instead of subshell, Samarium carries 2 in shell 1, 8 in shell 2, 18 in shell 3, 24 in shell 4, 8 in shell 5, 2 in shell 6. The outermost shell holds 2 electrons — the ones that do all the bonding.

How to derive it yourself

Follow the aufbau order (1s → 2s → 2p → 3s → 3p → 4s → 3d → …), pouring 62 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 Samarium that gives [Xe] 4f^6 6s^2.

Students also ask

How many electron shells does Samarium have?

Samarium is in period 6, so its electrons occupy 6 shells, holding 2, 8, 18, 24, 8, 2 electrons respectively.

How many valence electrons does Samarium have?

Its outermost shell holds 2 electrons, so Samarium has 2 valence electrons that take part in bonding.

What is the noble-gas shorthand for Samarium?

The shorthand form is exactly [Xe] 4f^6 6s^2.