| Period | Group | |
|---|---|---|
| ◀ f12 ▶ | ||
| 1 | ||
| 2 | ||
| 3 | ||
| 4 | ||
| 5 | ||
| 6 |
68
Er
Erbium
[Xe] 6s2 4f12
|
|
| 7 |
100
Fm
Fermium
[Rn] 7s2 5f12
|
Tip: Hover over an element to compare its electron configuration to that of the element below it.