Electron Configuration of Platinum (Pt)
Platinum (Pt, Z = 78) has the electron configuration [Xe] 4f¹⁴ 5d⁹ 6s¹, filling 6 shells with 2, 8, 18, 32, 17, 1 electrons.
Looking for Platinum's electron configuration without wading through a whole chapter? Here is the direct answer first, then the tables and derivations examiners want to see. Every number on this page comes from the same engine that powers the interactive table. Need the whole picture instead — history, characteristics, uses, exam questions? The full Platinum page is one click away.
Platinum: every subshell, one by one
Read the configuration like a receipt: each line is one subshell, and the running total climbs exactly to 78 electrons — never one more, never one less.
| Subshell | Electrons | Total so far |
|---|---|---|
| [Xe] | 0 | 54 |
| 4f | 14 | 68 |
| 5d | 9 | 77 |
| 6s | 1 | 78 |
Electrons per shell (K, L, M…)
Grouped by principal quantum number instead of subshell, Platinum carries 2 in shell 1, 8 in shell 2, 18 in shell 3, 32 in shell 4, 17 in shell 5, 1 in shell 6. 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 78 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 Platinum that gives [Xe] 4f¹⁴ 5d⁹ 6s¹.
Note: Platinum is one of the textbook exceptions to strict aufbau filling — a half-filled or fully-filled d subshell buys extra stability, so its ground-state configuration is [Xe] 4f¹⁴ 5d⁹ 6s¹.
Students also ask
How many electron shells does Platinum have?
Platinum is in period 6, so its electrons occupy 6 shells, holding 2, 8, 18, 32, 17, 1 electrons respectively.
How many valence electrons does Platinum have?
Its outermost shell holds 1 electron, so Platinum has 1 valence electron that take part in bonding.
What is the noble-gas shorthand for Platinum?
The shorthand form is exactly [Xe] 4f¹⁴ 5d⁹ 6s¹.