36 Kr 83.798

Krypton

Noble Gas

Krypton (Kr) is a chemical element with atomic number 36, classified as a noble gas. At room temperature it is a gas. It was discovered in 1898 by William Ramsay, Morris Travers.

Properties

Atomic number
36
Atomic mass
83.798 u
Category
Noble Gas
Group
18
Period
4
Block
p-block
Electron configuration
[Ar] 3d¹⁰ 4s² 4p⁶
Phase at STP
Gas
Density
3.733 g/L
Melting point
115.79 K (-157.4 °C)
Boiling point
119.93 K (-153.2 °C)
Electronegativity
3
Atomic radius
88 pm
Ionization energy
14 eV
Discovery
1898 · William Ramsay, Morris Travers

Common uses

High-performance light bulbs, lasers, insulating windows

Did you know?

Named after Greek word for 'hidden' and used in Superman's home planet.