Ir
192.220Iridium
İridyum
Iridium is a dense, corrosion-resistant platinum-group metal with atomic number 77. It is known for iridium spark plugs, Ir-192 brachytherapy, OLED phosphors, oxygen-evolution catalysts and the K-Pg boundary iridium anomaly.
77
192.22 g/mol
[Xe] 4f¹⁴ 5d⁷ 6s²
2 | 8 | 18 | 32 | 15 | 2
2.2
22.56 g/cm³
2445.8 °C
4427.9 °C
Smithson Tennant
Iridium was discovered in 1803 by Smithson Tennant in platinum ore residues. Its name comes from Iris, the rainbow, because many iridium salts show vivid colors.
Iridium-191
Natural abundance: About 37.3%. Stable natural iridium isotope.Iridium-192
Half-life: About 73.8 days. Artificial gamma-emitting isotope used in brachytherapy and industrial radiography.Iridium-193
Natural abundance: About 62.7%. Most abundant stable natural iridium isotope.IrO₂
Iridium(IV) OxideHighly active oxygen-evolution catalyst for acidic electrolysis systems.Ir(ppy)₃
Tris(phenylpyridine)iridiumPhosphorescent emitter used in OLED materials research and displays.IrCl₃
Iridium(III) ChloridePrecursor for iridium coordination and organometallic catalysts.- Iridium or platinum-iridium spark plug electrodes for long service life
- Iridium-192 sources for brachytherapy and industrial radiography
- Iridium oxide catalysts for oxygen evolution in acidic electrolysis
- Phosphorescent iridium complexes in OLED display materials
- Corrosion-resistant crucibles, electrodes and high-temperature alloys
Iridium has no known essential biological role. Iridium-192 is used as a sealed radiation source in brachytherapy and industrial radiography under controlled conditions.
- A global iridium-rich layer at the K-Pg boundary helped support the asteroid-impact explanation for the dinosaur extinction event.
- Iridium is among the most corrosion-resistant metals known.
- Iridium complexes can harvest triplet excitons, which makes them important in phosphorescent OLED technology.
- Iridium spark plug tips can be very small because iridium resists melting and erosion.
- Iridium has atomic number 77 and is a platinum-group metal.
- Its electron configuration is [Xe] 4f¹⁴ 5d⁷ 6s².
- Common oxidation states include +3 and +4.
- Remember iridium for the K-Pg boundary anomaly, spark plugs, Ir-192 and OLED emitters.
What is the atomic number of iridium?
The atomic number of iridium is 77.
What is the electron configuration of iridium?
Iridium has the electron configuration [Xe] 4f¹⁴ 5d⁷ 6s².
What is iridium used for?
Iridium is used in spark plugs, Ir-192 radiation sources, OLED emitters, oxygen-evolution catalysts and corrosion-resistant equipment.
What is the iridium anomaly?
The iridium anomaly is an unusually high iridium concentration at the K-Pg boundary, linked to the asteroid impact associated with dinosaur extinction.
What is iridium-192 used for?
Iridium-192 is used as a sealed gamma source in cancer brachytherapy and industrial radiography.
Why is iridium used in spark plugs?
Iridium has a high melting point and excellent corrosion resistance, helping spark plug electrodes last longer.