Krypton is located on the fourth period and eighteenth group in the periodic table of elements. It is a colorless gas with a boiling point of -153 degrees Celsius.When exited, it glows greenish-yellow. Krypton is an inert gas and reacts only with fluorine. It was discovered in 1898 by William Ramsey Morris Travers.

Krypton is used in lighting and lasers. Its radioactive isotope Krypton-85 was also used to spy on soviet nuclear activity during the cold war.