Palladium (Pd)
[Kr] 4d¹⁰, an exception. 0 unpaired electrons, period 5, group 10, d block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
PdPalladium, Z = 46, 106.42 u
[Kr] 4d10
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰
- Blockd block
- Period5
- Group10
- Valence10
- Unpaired0
- MagneticDia
Last electron 4d
- n4shell
- l2d subshell
- m+2orbital
- s−½spin down
Why Pd is an exception
Plain filling would give [Kr] 4d⁸ 5s². The 4d and 5s levels are very close here, and a full 4d¹⁰ is extra stable, so both 5s electrons move into 4d and 5s is left empty.
Step by step
- Palladium has 46 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁸.
- That gives [Kr] 4d⁸ 5s², but the accepted configuration is [Kr] 4d¹⁰. The 4d and 5s levels are very close here, and a full 4d¹⁰ is extra stable, so both 5s electrons move into 4d and 5s is left empty.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰.
- Replace the krypton core with [Kr]: [Kr] 4d¹⁰.
Palladium (Pd): the numbers
| Atomic number | 46 |
|---|---|
| Atomic mass | 106.42 u |
| Period | 5 |
| Group | 10 |
| Block | d block |
| Valence electrons | 10 |
| Unpaired electrons | 0 |
| Magnetic | diamagnetic |
| Last electron | 4d: n = 4, l = 2, m = +2, s = −1/2 |
Palladium (Pd): quick answers
What is the electronic configuration of palladium?
Palladium has 46 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰, or [Kr] 4d¹⁰ in short.
Why is palladium [Kr] 4d¹⁰ and not [Kr] 4d⁸ 5s²?
The 4d and 5s levels are very close here, and a full 4d¹⁰ is extra stable, so both 5s electrons move into 4d and 5s is left empty.
What are the quantum numbers of the last electron of palladium?
The last electron goes into 4d: n = 4, l = 2, m = +2, s = −1/2. Orbitals fill from m = −l up, spin +½ first.