Xenon

Helium, neon, argon, krypton, xenon and radon are noble gases.

Our atmosphere contains 21% oxygen, which is necessary for us to breathe, 78% nitrogen, and 0.9% argon. The other 0.1% consists of water vapor, carbon dioxide, neon, methane, krypton, helium, xenon, hydrogen, nitrous oxide, carbon monoxide, nitrogen dioxide, sulfur dioxide, and ozone.

Xenon is the 54th chemical element. It is colorless, odorless and tasteless.

Argon and xenon gas can also be used in cold gas thrusters due to their inertness.