Xenon is a chemical element with the symbol Xe and atomic number 54. It is a colorless, odorless, tasteless noble GAS found in the Earth's atmosphere in trace amounts. Xenon is a member of the group 18 elements, also known as the noble gases. It is one of the five stable noble gases, along with helium, neon, argon, and krypton. Xenon is a GAS at standard temperature and pressure and is used in a variety of applications, including lighting, lasers, and medical imaging.