Full configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 5d¹ 6s²
In the short form, [Xe] stands for the 54 electrons of xenon, the noble gas before gadolinium. Only the electrons after it are written out.
Orbital diagram
Outer subshells only. Each box is an orbital; electrons fill singly first (Hund's rule), then pair up with opposite spins.
Why it's an exception
Gadolinium keeps a half-filled 4f⁷ and puts the next electron in 5d.
Configuration of gadolinium ions
| Ion | Configuration | Unpaired | Moment (BM) |
|---|---|---|---|
| Gd³⁺ | [Xe] 4f⁷ | 7 | 7.94 |
Moment is the spin-only magnetic moment μ = √(n(n + 2)) Bohr magnetons, where n is the number of unpaired electrons.
Nearby elements
| Z | Element | Configuration |
|---|---|---|
| 61 | Promethium | [Xe] 4f⁵ 6s² |
| 62 | Samarium | [Xe] 4f⁶ 6s² |
| 63 | Europium | [Xe] 4f⁷ 6s² |
| 65 | Terbium | [Xe] 4f⁹ 6s² |
| 66 | Dysprosium | [Xe] 4f¹⁰ 6s² |
| 67 | Holmium | [Xe] 4f¹¹ 6s² |
Questions students ask
What is the electronic configuration of gadolinium?
[Xe] 4f⁷ 5d¹ 6s², or in full, 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 5d¹ 6s². Gadolinium has atomic number 64.
How many electrons are in each shell of gadolinium?
2, 8, 18, 25, 9, 2 (K, L, M, N… shells in order).
How many unpaired electrons does gadolinium have?
8 in the ground state, so gadolinium atoms are paramagnetic.
What is the electronic configuration of Gd³⁺?
[Xe] 4f⁷, with 7 unpaired electrons.
Why is gadolinium an exception?
Gadolinium keeps a half-filled 4f⁷ and puts the next electron in 5d.