Iridium Electron Configuration

Complete electron configuration reference for iridium (Ir, Z=77): full notation 1s²...6s², noble-gas shorthand [Xe] 4f¹⁴ 5d⁷ 6s², orbital box diagram, and key atomic data.

Z = 77 Ir Iridium

Iridium — Electron Configuration

Atomic number 77 · Transition metal (PGM) · Period 6, Group 9 · d-block

[Xe] 4f¹⁴ 5d⁷ 6s² 77 electrons 9 valence e⁻ 5d⁷ 6s²

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
4f f orbitals, shell n=4 14 14 4f¹⁴
5s s orbital, shell n=5 2 2 5s²
5p p orbitals, shell n=5 6 6 5p⁶
5d d orbitals, shell n=5 (valence) 7 10 5d⁷
6s s orbital, shell n=6 (valence) 2 2 6s²
Total 77

Noble-Gas Shorthand

[Xe] 4f¹⁴ 5d⁷ 6s²

[Xe] = filled xenon core (54 electrons, 1s through 5p).

Valence Subshells

5d⁷ 6s²

9 valence electrons across the 5d and 6s subshells.

Shell Fill Summary

Shell 1 (n=1) — 1s² 2 / 2 (100%)
Shell 2 (n=2) — 2s² 2p⁶ 8 / 8 (100%)
Shell 3 (n=3) — 3s² 3p⁶ 3d¹⁰ 18 / 18 (100%)
Shell 4 (n=4) — 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 32 / 32 (100%)
Shell 5 (n=5) — 5s² 5p⁶ 5d⁷ 15 / 50 (30%)
Shell 6 (n=6) — 6s² 2 / 72 (3%)

Shell 5 can hold up to 50 electrons (5s + 5p + 5d + 5f + 5g); iridium uses only 15. Shell 6 currently holds only the 6s pair.

Summary

Complete electron configuration reference for iridium (Ir, Z=77): full notation 1s²...6s², noble-gas shorthand [Xe] 4f¹⁴ 5d⁷ 6s², orbital box diagram, and key atomic data.

How it works

  1. Electrons fill subshells in order of increasing energy following the Aufbau principle.
  2. The [Xe] core (54 electrons) replaces the filled inner shells 1s through 5p.
  3. The 4f subshell fills completely with 14 electrons across the lanthanide series before iridium is reached.
  4. After the 4f shell, electrons enter the 5d subshell; iridium has 7 electrons there.
  5. The outermost 6s subshell holds 2 paired electrons.
  6. The 5d⁷ 6s² valence arrangement determines iridium's +3 and +4 oxidation states.

Use cases

  • Homework and exam reference for Period 6 d-block electron configurations.
  • Understand how the 4f subshell influences 5d/6s filling in Period 6 metals.
  • Compare iridium to neighboring elements osmium (5d⁶ 6s²) and platinum (5d⁹ 6s¹).
  • Study why iridium is one of the densest and most corrosion-resistant metals.
  • Teaching orbital filling rules across the 5d transition series.
  • Verify quantum numbers and subshell occupancy for iridium.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu