[17] Although generally unreactive, it can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized.

[25] Xenon is also used to search for hypothetical weakly interacting massive particles[26] and as a propellant for ion thrusters in spacecraft.

[31][32] Ramsay suggested the name xenon for this gas from the Greek word ξένον xénon, neuter singular form of ξένος xénos, meaning 'foreign(er)', 'strange(r)', or 'guest'.

[35] During the 1930s, American engineer Harold Edgerton began exploring strobe light technology for high speed photography.

He tested the effects of varying the breathing mixtures on his subjects, and discovered that this caused the divers to perceive a change in depth.

[57] When metallized, xenon appears sky blue because it absorbs red light and transmits other visible frequencies.

[64] After this separation, generally performed by fractional distillation in a double-column plant, the liquid oxygen produced will contain small quantities of krypton and xenon.

Within the Solar System, the nucleon fraction of xenon is 1.56×10−8, for an abundance of approximately one part in 630 thousand of the total mass.

[69][a] This abundance remains unexplained, but may have been caused by an early and rapid buildup of planetesimals—small, sub-planetary bodies—before the heating of the presolar disk;[70] otherwise, xenon would not have been trapped in the planetesimal ices.

[71] Unlike the lower-mass noble gases, the normal stellar nucleosynthesis process inside a star does not form xenon.

[72] Instead, xenon is formed during supernova explosions during the r-process,[73] by the slow neutron-capture process (s-process) in red giant stars that have exhausted their core hydrogen and entered the asymptotic giant branch,[74] and from radioactive decay, for example by beta decay of extinct iodine-129 and spontaneous fission of thorium, uranium, and plutonium.

This phenomenon called xenon poisoning can cause significant problems in restarting a reactor after a scram or increasing power after it had been reduced and it was one of several contributing factors in the Chernobyl nuclear accident.

[76][77] Stable or extremely long lived isotopes of xenon are also produced in appreciable quantities in nuclear fission.

Under adverse conditions, relatively high concentrations of radioactive xenon isotopes may emanate from cracked fuel rods,[92] or fissioning of uranium in cooling water.

Since this isotope is generated by radioactive decay, the result may indicate that Mars lost most of its primordial atmosphere, possibly within the first 100 million years after the planet was formed.

[134] Such clathrate hydrates can occur naturally under conditions of high pressure, such as in Lake Vostok underneath the Antarctic ice sheet.

When xenon atoms becomes energized, however, they can form an excimer (excited dimer) until the electrons return to the ground state.

[143] Continuous, short-arc, high pressure xenon arc lamps have a color temperature closely approximating noon sunlight and are used in solar simulators.

They are an excellent source of short wavelength ultraviolet radiation and have intense emissions in the near infrared used in some night vision systems.

Xenon is used as a starter gas in metal halide lamps for automotive HID headlights, and high-end "tactical" flashlights.

[148][149] The first excimer laser used a xenon dimer (Xe2) energized by a beam of electrons to produce stimulated emission at an ultraviolet wavelength of 176 nm.

[169] Xenon allosterically reduces ATP mediated channel activation inhibition independently of the sulfonylurea receptor1 subunit, increasing KATP open-channel time and frequency.

[186][187] In nuclear energy studies, xenon is used in bubble chambers,[188] probes, and in other areas where a high molecular weight and inert chemistry is desirable.

[190] Liquid xenon is used in calorimeters[191] to measure gamma rays, and as a detector of hypothetical weakly interacting massive particles, or WIMPs.

Liquid xenon is useful for these experiments because its density makes dark matter interaction more likely and it permits a quiet detector through self-shielding.

Xenon is the preferred propellant for ion propulsion of spacecraft because it has low ionization potential per atomic weight and can be stored as a liquid at near room temperature (under high pressure), yet easily evaporated to feed the engine.

Applied at pressures from 0.5 to 5 MPa (5 to 50 atm) to a protein crystal, xenon atoms bind in predominantly hydrophobic cavities, often creating a high-quality, isomorphous, heavy-atom derivative that can be used for solving the phase problem.

[196][197] Xenon gas can be safely kept in normal sealed glass or metal containers at standard temperature and pressure.

[199] Xenon is non-toxic, although it does dissolve in blood and belongs to a select group of substances that penetrate the blood–brain barrier, causing mild to full surgical anesthesia when inhaled in high concentrations with oxygen.

[202] The gas sulfur hexafluoride is similar to xenon in molecular weight (146 versus 131), less expensive, and though an asphyxiant, not toxic or anesthetic; it is often substituted in these demonstrations.