Iridium (Ir)
Iridium (Ir, element 77) is a transition metal in group 9, period 6. Atomic mass 192.217, electron configuration [Xe] 4f¹⁴ 5d⁷ 6s², uses and facts.
About Iridium
Iridium is a transition metal with the symbol Ir and atomic number 77. It is a solid at room temperature, and it sits in group 9, period 6 of the periodic table. Iridium was discovered in 1803 by Smithson Tennant.
Iridium key facts
- Atomic number: 77
- Symbol: Ir
- Atomic mass: 192.217 u
- Category: transition metal
- Group: 9
- Period: 6
- State at room temperature: solid
- Electron configuration: [Xe] 4f¹⁴ 5d⁷ 6s²
- Electronegativity (Pauling): 2.2
- Melting point: 2719 K (2445.85 °C)
- Boiling point: 4403 K (4129.85 °C)
- Density: 22.56 g/cm³
- Common oxidation states: −3, −1, 0, +1, +2, +3, +4, +5, +6
Electron configuration
The electron configuration of iridium is [Xe] 4f¹⁴ 5d⁷ 6s². The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells.
Uses of iridium
- Spark plugs
- Crucibles
- The official kilogram (alloy)
Did you know?
A thin layer of iridium in rock worldwide marks the asteroid impact that killed the dinosaurs 66 million years ago.
Other elements in group 9 and neighbours
Frequently asked questions
What is the atomic number of iridium?
The atomic number of iridium is 77, which means every iridium atom has 77 protons.
What is the electron configuration of iridium?
The electron configuration of iridium is [Xe] 4f¹⁴ 5d⁷ 6s².
What group and period is iridium in?
Iridium is a transition metal in group 9, period 6.
What state is iridium at room temperature?
Iridium is a solid at room temperature.
What is iridium used for?
Iridium is used for spark plugs, crucibles, the official kilogram (alloy).