Krypton was discovered in 1898 by Sir William Ramsay and his student Morris Travers in the residue left after liquid air had nearly boiled away. Krypton was left in the residue after boiling away water, oxygen, nitrogen, helium, and argon from the sample of air. Krypton is present in the air at about 1 ppm. Neon was discovered by a similar procedure by the same workers just a few weeks later.

• The Earth's atmosphere is made of about 0.0001% Krypton
• The melting point of Krytpon is -157.36 ºC
• The boiling point of Krypton is -153.22 ºC
• Since Krypton is a noble gas it doesn't combine with other elements because it barely has enough electrons to fill it's outer shell

Krypton is present to a small quantities in the atmosphere and is obtained as a byproduct from the liquid is isolated by the separation of the air. This would not normally be carried out in the laboratory and krypton is available commercially in cylinders at high pressure

• Used with argon as a low-pressure filling gas for fluorescent lights
• used in some photographic flash lamps for high-speed photography, lamps, UV-laser spectral line used for international measurement of a meter

-Krypton is not mined because it is a gas and mostly solid elements are mined