Krypton is used in some fluorescent light bulbs and photographic flashes for high-speed cameras. It is also combined with other gases to create luminous signs. The elevated cost of obtaining krypton negates its use in most applications.
Krypton was discovered by Scottish chemist Sir William Ramsay and English chemist Morris M. Travers in May 1898. The pair were studying liquefied air and noticed that tiny amounts of liquid krypton were left behind when other components of liquid air had boiled away. Notably, the atmosphere of the Earth is made from 0.0001 percent krypton.
Krypton comes from the Greek word "kryptos," which means hidden.