Silver (Ag)
[Kr] 4d¹⁰ 5s¹, an exception. 1 unpaired electron, period 5, group 11, 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.
AgSilver, Z = 47, 107.868 u
[Kr] 4d10 5s1
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s¹
- Blockd block
- Period5
- Group11
- Valence11
- Unpaired1
- MagneticPara
Last electron 4d
- n4shell
- l2d subshell
- m+2orbital
- s−½spin down
Why Ag is an exception
Plain filling would give [Kr] 4d⁹ 5s². A completely filled d subshell (d¹⁰) is extra stable, for the same reasons of symmetry and exchange energy. So one s electron moves into d.
Step by step
- Silver has 47 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁹.
- That gives [Kr] 4d⁹ 5s², but the accepted configuration is [Kr] 4d¹⁰ 5s¹. A completely filled d subshell (d¹⁰) is extra stable, for the same reasons of symmetry and exchange energy. So one s electron moves into d.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s¹.
- Replace the krypton core with [Kr]: [Kr] 4d¹⁰ 5s¹.
Silver (Ag): the numbers
| Atomic number | 47 |
|---|---|
| Atomic mass | 107.868 u |
| Period | 5 |
| Group | 11 |
| Block | d block |
| Valence electrons | 11 |
| Unpaired electrons | 1 |
| Magnetic | paramagnetic |
| Last electron | 4d: n = 4, l = 2, m = +2, s = −1/2 |
Silver (Ag): quick answers
What is the electronic configuration of silver?
Silver has 47 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s¹, or [Kr] 4d¹⁰ 5s¹ in short.
Why is silver [Kr] 4d¹⁰ 5s¹ and not [Kr] 4d⁹ 5s²?
A completely filled d subshell (d¹⁰) is extra stable, for the same reasons of symmetry and exchange energy. So one s electron moves into d.
What are the quantum numbers of the last electron of silver?
The last electron goes into 4d: n = 4, l = 2, m = +2, s = −1/2. Orbitals fill from m = −l up, spin +½ first.