(Gr. xenon, stranger) Discovered by Ramsay and Travers in 1898. Xenon is found in the Martian atmosphere and in small quantities in the earth's atmosphere. In 1962 Neil Bartlett discovered the first real compound of a noble gas, XePtF. Although it is a inert gas, it forms compounds with F, Pt and O. Xenon trioxide is explosive. So far, a total of 80 compounds have been made with O and F.