Krypton

Atomic number

36

Atomic mass (u)

83.80

Category

Noble gas

Standard state

Gas

Melting point

-157.36 °C (115.79 K)

Boiling point

-153.22 °C (119.93 K)

Density (g/cm³)

0.003733

Electronegativity (Pauling)

3

Electron configuration

[Ar]4s2 3d10 4p6

Oxidation states

0

Atomic radius (pm)

202

First ionization energy (eV)

14.000

Discovery & recognition

Discovery year / period (PubChem)

1898

Discovery credited to (RSC)

Sir William Ramsay and Morris Travers

Date or period recorded by RSC

1898

Discovery place

Not supplied in the structured record; see the RSC history source.

An ancient date does not identify a first human discovery. Different references may date observation, isolation and formal recognition differently.

Natural occurrence & production

The creation of an element’s nuclei and its concentration into terrestrial deposits are different processes. The occurrence note below concerns its presence or production on Earth; it is not a complete account of nucleosynthesis.

“Krypton is one of the rarest gases in the Earth’s atmosphere.”

Royal Society of Chemistry · occurrence excerpt ↗

Continue the research

Reference values are not product specifications. Blank values have not been estimated. For superheavy elements, some properties and family assignments are theoretical or incompletely measured.