77Ir192.22
Iridium
Transition metalsHard, shiny metals that conduct heat and electricity well and often form coloured compounds.
[Xe] 4f¹⁴ 5d⁷ 6s²
- Atomic number
- 77
- Atomic mass
- 192.22
- Protons
- 77
- Neutrons
- 115 (most common)
- Electrons
- 77
- Shells
- 2, 8, 18, 32, 15, 2
- State at 25 °C
- Solid
- Position
- Group 9, period 6
Proton (+)Neutron (0)Electron (−)
Discovered bySmithson Tennant, 1803Smithson Tennant: 2 elements
Named from Iris, the Greek goddess of the rainbow, because its salts are so colourful.
Did you know?
- A worldwide layer of iridium in 66-million-year-old rocks points to the asteroid that ended the dinosaurs.
- It is one of the most corrosion-resistant metals.
Where it's found
- Platinum ores
- Meteorites
What it's used for
- Spark plugs
- The old standard metre and kilogram (platinum–iridium alloy)
Try it
There's no safe home experiment for Iridium. Explore it with the animated atom above instead.