An extremely unreactive gaseous element occurring in the atmosphere to the extent of 18 parts per million. Neon, one of the inert gases, is obtained by the fractional distillation of air. It is colorless but glows reddish-orange in an electric discharge and is used in fluorescent tubes and gas lasers. The most common isotope is 20Ne (90.92%). Neon was discovered in 1898 by Scottish chemist William Ramsay and English chemist Morris W. Travers.