Krypton [Kr] 

CAS-ID: 7439-90-9

An: 36 N: 48

Am: 83.798 g/mol

Group No: 18

Group Name: Noble Gases

Block: p-block  Period: 4

State: Gas

Colour: Colourless Classification: Non-metallic

Boiling Point: 119.93K (-153.22°C)

Melting Point: 115.79K (-157.36°C)

Critical temperature: 209.4K (-63.7°C)

Density: 3.749g/l

Availability: Krypton is present in the air at about 1 ppm.

Discovery Information

Who: Sir William Ramsey, M.W. Travers

When: 1898

Where: Great Britain

Name Origin

Greek: kryptos (hidden).

 "Krypton" in different languages.

Sources

Forms around 1 millionth of the atmosphere. It is obtained from production of liquid air.

It is one of the products of uranium fission.

Abundance

 Universe: 0.04 ppm (by weight)

 Atmosphere: 1.14 ppm

 Earth's Crust: 1 x 10-5 ppm

 Seawater: 2.1 x 10-4 ppm

Uses

Used in fluorescent bulbs, flashbulbs, and as a wavelength standard.

One major use of krypton is the krypton fluorine laser. Certain amounts of energy are added to force krypton gas to react with fluorine gas to become KrF excited state complex.

The compound will decompose once the energy supply stops. During the decomposition process, the excess energy stored in the excited state complex will be emitted in the form of strong ultraviolet laser radiation.

History

Krypton was discovered in Great Britain in 1898 by Sir William Ramsay and Morris Travers in residue left from evaporating nearly all components of liquid air.