Silver Electron Configuration
Reference for silver's anomalous electron configuration ([Kr] 4d¹⁰ 5s¹), orbital box diagram, and key atomic data for Ag (Z=47).
Silver — Electron Configuration
Atomic number 47 · Transition metal · Period 5, Group 11 · d-block
Anomalous Configuration — Aufbau Exception
Aufbau predicts [Kr] 4d⁹ 5s², but silver adopts [Kr] 4d¹⁰ 5s¹. A completely filled 4d¹⁰ subshell releases more exchange energy than the 4s²-style pairing, making the anomalous arrangement more stable. The same pattern occurs in copper (Z=29) and gold (Z=79).
Subshell Breakdown
| Subshell | Type | Electrons | Max Capacity | Notation |
|---|---|---|---|---|
| 1s | s orbital, shell n=1 | 2 | 2 | 1s² |
| 2s | s orbital, shell n=2 | 2 | 2 | 2s² |
| 2p | p orbitals, shell n=2 | 6 | 6 | 2p⁶ |
| 3s | s orbital, shell n=3 | 2 | 2 | 3s² |
| 3p | p orbitals, shell n=3 | 6 | 6 | 3p⁶ |
| 3d | d orbitals, shell n=3 | 10 | 10 | 3d¹⁰ |
| 4s | s orbital, shell n=4 | 2 | 2 | 4s² |
| 4p | p orbitals, shell n=4 | 6 | 6 | 4p⁶ |
| 4d | d orbitals, shell n=4 | 10 | 10 | 4d¹⁰ |
| 5s | s orbital, shell n=5 (anomalous) | 1 | 2 | 5s¹ |
| Total | 47 | |||
Full Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s¹
All subshells written explicitly.
Noble-Gas Shorthand
[Kr] 4d¹⁰ 5s¹
[Kr] = 1s²…4p⁶ (krypton's filled core, Z=36).
Expected vs. Actual
4d⁹ 5s² (Aufbau)
4d¹⁰ 5s¹ (actual)
Filled d¹⁰ wins over s².
Shell Fill Summary
Shell 5 can hold up to 50 electrons (5s + 5p + 5d + 5f + 5g). Silver uses only 1 slot — the 5s¹. This makes the next element (cadmium) add its electron to 5s to reach 5s².
Group 11 Coinage Metals — All Three Are Anomalous
| Element | Z | Expected (Aufbau) | Actual |
|---|---|---|---|
| Copper (Cu) | 29 | [Ar] 3d⁹ 4s² | [Ar] 3d¹⁰ 4s¹ |
| Silver (Ag) | 47 | [Kr] 4d⁹ 5s² | [Kr] 4d¹⁰ 5s¹ |
| Gold (Au) | 79 | [Xe] 4f¹⁴ 5d⁹ 6s² | [Xe] 4f¹⁴ 5d¹⁰ 6s¹ |
Summary
Reference for silver's anomalous electron configuration ([Kr] 4d¹⁰ 5s¹), orbital box diagram, and key atomic data for Ag (Z=47).
How it works
- The Aufbau principle fills subshells from lowest to highest energy: …4s → 3d → 4p → 5s → 4d.
- For silver (Z=47), the naive prediction would be [Kr] 4d⁹ 5s², placing 9 electrons in 4d and 2 in 5s.
- Instead, one electron migrates from 5s to complete the 4d subshell, giving the actual configuration [Kr] 4d¹⁰ 5s¹.
- A completely filled 4d¹⁰ subshell has maximum exchange energy, making it more stable than the partially filled 4d⁹ 5s².
- The same anomaly appears in copper (Z=29) and gold (Z=79) — all three are Group 11 coinage metals.
- Noble-gas notation replaces the krypton core with [Kr], leaving [Kr] 4d¹⁰ 5s¹ as the standard abbreviated form.
Use cases
- Quick reference for chemistry homework on d-block anomalies and Aufbau exceptions.
- Understand why silver's 4d¹⁰ 5s¹ is more stable than the expected 4d⁹ 5s².
- Learn how silver forms Ag⁺ ions by losing the single 5s¹ electron.
- Visualize orbital filling for Period 5 transition metals using the orbital diagram.
- Compare silver to copper and gold — the three Group 11 coinage metal exceptions.
- Teaching aid for exchange energy, Hund's rule, and d-block chemistry lessons.
- Verify quantum numbers for the outermost subshells of silver.