Xenon (read as xiān old translation 氠, 氥) is a chemical element, its elemental symbol is XE, its atomic number is 54, is a colorless and tasteless rare gas, the discharge is blue. Trace amounts of xenon exist in the Earth's atmosphere. In addition to individual compounds, the xenon compounds are colorless.
The stable isotopes of the known xenon have 9 species (see Xenon isotopes). It also has 40 of unstable radioactive isotopes. The radioactive isotope of xenon is an important tool to study the early history of the solar system. Xenon-135 is one of the products of nuclear fission and serves as a neutron absorber for nuclear reactors. Xenon can be used to make xenon lights and xenon arc lamps, as well as a general anesthetic. The first Excimer laser uses the xenon excitation dimer Xe2 as the laser active medium, and the first laser diode uses xenon light as a laser pump. Xenon is used to search for imaginary large-mass weakly interacting particles, which is a propellant in a new type of spacecraft ion thruster.