xenon

Xenon is a chemical element with the symbol Xe and atomic number 54. It is a colorless, odorless, tasteless noble gas in group 18 of the periodic table. Xenon is one of the heaviest naturally occurring noble gases and is characteristically inert under standard conditions, though it can form a few compounds at high pressures or with strong oxidizing agents.

In Earth's atmosphere xenon is extremely rare, about 0.087 parts per million by volume. It is obtained commercially by separating air through cryogenic distillation, typically as a byproduct of oxygen-nitrogen separation. It can also be recovered from spent lighting products and other industrial sources.

Natural xenon consists of several isotopes; the most abundant are Xe-132, Xe-129, Xe-131, Xe-134, and Xe-136. The standard atomic weight is about 131.29 g/mol. Xenon has multiple applications in science and industry due to its high atomic number and scintillation properties.

Major uses include lighting: xenon arc lamps, high-intensity discharge lamps, and xenon headlights for vehicles and cinema projectors. In medicine, xenon gas has been used as an anesthetic because of rapid onset, low toxicity, and rapid recovery, though its cost limits routine use. In space exploration, xenon is used as a propellant for ion thrusters in spacecraft. In research, xenon gas is employed in detectors for particle physics and cosmology, and hyperpolarized xenon-129 is explored for magnetic resonance imaging of lungs.

Safety: Xenon is an inert gas and nonflammable, but at high concentrations in enclosed spaces it can displace oxygen and pose an asphyxiation risk. Storage requires standard gas-handling precautions.