Key information
Atomic number: 
36
Atomic weight: 
83.8
Density: 
2600 kg/m³
Boiling point: 
121.16° K
Melting point: 
115.86° K
Heat vapour: 
9.05 kJ/mol
Heat fusion: 
1.63 kJ/mol
Group: 
Noble Gases

Krypton is a trace element in the Earth's atmosphere - it is present at about 114 parts per million in air. It was discovered in 1898, by the Scottish chemist William Ramsay and English chemist Morris W. Travers. Ramsay chilled a sample of the atmosphere until it became a liquid, then warmed the liquid and captured the gases as they boiled off.

Electron Shell: