Rhenium has 75 electrons arranged as 2, 8, 18, 32, 13, 2 across 6 shells, which is why it sits in period 6.
Start from the previous noble gas core, written in square brackets, then add the remaining electrons in filling order. For rhenium that gives [Xe] 4f14 5d5 6s2.
| Atomic number | 75 |
| Symbol | Re |
| Atomic mass | 186.21 u |
| Group | 7 |
| Period | 6 |
| Block | d-block |
| Category | Transition metal |
| Element | Configuration |
|---|---|
| Manganese | [Ar] 3d5 4s2 |
| Technetium | [Kr] 4d5 5s2 |
| Bohrium | [Rn] 5f14 6d5 7s2 |