36Kr83.798
Krypton
Noble gasesColourless gases with full outer shells, so they hardly ever react.
[Ar] 3d¹⁰ 4s² 4p⁶
- Atomic number
- 36
- Atomic mass
- 83.798
- Protons
- 36
- Neutrons
- 48 (most common)
- Electrons
- 36
- Shells
- 2, 8, 18, 8
- State at 25 °C
- Gas
- Position
- Group 18, period 4
Proton (+)Neutron (0)Electron (−)
Discovered byWilliam Ramsay and Morris Travers, 1898William Ramsay: 5 elementsMorris Travers: 3 elements
They found krypton in the leftovers of evaporating liquid air. Its name means “hidden” in Greek.
Did you know?
- From 1960 to 1983, the metre was defined using light from krypton-86.
- Like other noble gases, it barely reacts.
Where it's found
- Tiny traces in the air
What it's used for
- Energy-saving windows
- Photography flash lamps
- Some lasers
Try it
There's no safe home experiment for Krypton. Explore it with the animated atom above instead.