Iridium (Ir): Electron Configuration, Properties and Uses
Iridium (Ir): Electron Configuration, Properties and Uses
Electron configuration [Xe] 6s2 4f14 5d7 · group 9 · period 6 · Ar 192.22
Iridium data
- Atomic number
- 77
- Relative atomic mass
- 192.22
- Group
- 9
- Period
- 6
- Block
- d
- Category
- Transition metal
- Electron configuration
- [Xe] 6s2 4f14 5d7
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d7
- Electrons per shell
- 2, 8, 18, 32, 15, 2 (K L M N O P)
- Valence electrons
- 9
- Electronegativity (Pauling)
- 2.2
- First ionisation energy
- 9.1 eV
- Atomic radius (van der Waals)
- 202 pm
- State at room temperature
- Solid
- Melting point
- 2446 °C
- Boiling point
- 4428 °C
- Density
- 22.42 g/cm³
- Common oxidation states
- +4, +3
- Discovered
- 1803
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 18 · N 32 · O 15 · P 2
Orbital diagram (outer electrons)
About iridium
Iridium, symbol Ir, is element number 77 in the periodic table. It is a transition metal in group 9, period 6, d-block. The element was discovered in 1803. Iridium is a solid at room temperature, melting at 2446 °C and boiling at 4428 °C.
Iridium electron configuration
The electron configuration of iridium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d7, or in short [Xe] 6s2 4f14 5d7. Its electrons occupy 6 shells: K = 2, L = 8, M = 18, N = 32, O = 15, P = 2. For transition metals, valence electrons are counted from the 6s and 5d subshells: 2 + 7 = 9, matching group 9. When it forms cations, electrons leave the outermost subshell first: Ir3+ = [Xe] 4f14 5d6; Ir4+ = [Xe] 4f14 5d5.
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s2(12) → 3p6(18) → 4s2(20) → 3d10(30) → 4p6(36) → 5s2(38) → 4d10(48) → 5p6(54) → 6s2(56) → 4f14(70) → 5d7(77)
Uses of iridium
Well-known applications of iridium include spark plugs, crucibles for growing crystals, PEM water-electrolysis catalysts and Ir-192 for industrial radiography. For research and analysis you can browse iridium compounds in the AMI Scientific catalogue.
Safety
Iridium metal is generally safe to handle, but avoid breathing its dust and read the SDS before using Iridium compounds. Always read the safety data sheet (SDS) before working with a chemical.
Other elements in group 9
Frequently asked questions
What is the electron configuration of iridium?
The electron configuration of iridium (Ir, atomic number 77) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d7, or [Xe] 6s2 4f14 5d7 in short. By shell: 2, 8, 18, 32, 15, 2.
How many valence electrons does iridium have?
Iridium has 9 valence electrons.
Which group and period is iridium in?
Iridium is in group 9, period 6, d-block.
What is the atomic mass of iridium?
The relative atomic mass of iridium is 192.22. Use it to calculate molar mass with the molar mass calculator.
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