Electron Configuration of Mendelevium (Md)
Mendelevium (Md, Z = 101) has the electron configuration [Rn] 5f^13 7s^2, filling 7 shells with 2, 8, 18, 32, 31, 8, 2 electrons.
Teachers call it "one fact, fully handled" — exactly what this page does for Mendelevium. 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 Mendelevium page is one click away.
Mendelevium: every subshell, one by one
Start from 1s and follow the running total: this is exactly how examiners expect you to build Mendelevium's configuration on paper.
| Subshell | Electrons | Total so far |
|---|---|---|
| [Rn] | 0 | 86 |
| 5f | 13 | 99 |
| 7s | 2 | 101 |
Electrons per shell (K, L, M…)
Grouped by principal quantum number instead of subshell, Mendelevium carries 2 in shell 1, 8 in shell 2, 18 in shell 3, 32 in shell 4, 31 in shell 5, 8 in shell 6, 2 in shell 7. 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 101 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 Mendelevium that gives [Rn] 5f^13 7s^2.
Students also ask
How many electron shells does Mendelevium have?
Mendelevium is in period 7, so its electrons occupy 7 shells, holding 2, 8, 18, 32, 31, 8, 2 electrons respectively.
How many valence electrons does Mendelevium have?
Its outermost shell holds 2 electrons, so Mendelevium has 2 valence electrons that take part in bonding.
What is the noble-gas shorthand for Mendelevium?
The shorthand form is exactly [Rn] 5f^13 7s^2.