Xenon (Xe) is a noble gas, found on the periodic table of elements all the way over in the far right column with the rest of the noble gases. It is quite heavy for a gas. Atomic number 54 and a standard atomic weight of a whopping 131.293, meaning that it has a whole bunch of neutrons inside that atomic nucleus along with all 54 protons. Only one noble gas is found below it in the column and that is Radon (Ra). Preceding Xenon is Helium (He) with 2 protons and 2 electrons, Neon (Ne) Atomic number 10, Argon (Ar) number 18, and then Krypton (Kr) number 36.
Noble gases are generally non-reactive. That means they don't easily form molecules with other elements or with themselves. Most elements do, but not the noble gases. The electrons that circle the nucleus fill their respective shell levels, so it is difficult to share electrons with other atoms. That is what makes noble gases special, because they don't react, not even with themselves. At one time they were even called Inert Gases, but that term has lost favor, in part because of Xenon.
You see, Xenon is extra special. Around 1961, it was found that by creating a gaseous compound made from one Platinum atom and 6 Flourine atoms (Platinum Hexaflouride), Xenon could react with the gas under certain conditions. Mainly, if you mixed the two gases in a chamber and then very slowly heated them up, they would form a new compound called Xenon Hexaflouride platinate. (If I got any of this wrong, forgive me, its been almost 30 years since my Chem Classes)
What made this special was that up until this discovery, it was thought that you couldn't combine noble gases with anything. As it turns out, you can make these gases do all sorts of things in a laboratory that you'd never find in nature.
Xenon has other uses. Put it in a tube and excite it with an electrostatic charge, and it emits a blue light that is now being used for automobile headlamps. NASA uses Xenon lights to light up their launch platforms at night. The brains over at Bell Labs discovered they could use to make lasers, and NASA decided to use Xenon as the propellant Ion drives for deep space vehicles. To keep it uncomplicated, Xenon is turned into plasma, passed through a grid to accelerate the ions and as it escapes out the drive, it produces thrust similar to that produced by a rocket, but at a much lower scale. Over time, the amount of thrust is huge, but at any particular moment, it is tiny. You couldn't use an ion drive to escape the atmosphere and fly into space, but you could use it head for the nearest star, if you've got a few hundred years to spend on the trip. Simple, right?
Speaking of atmosphere, would you ever think to inhale Xenon? Of course you would. In fact, Xenon is a byproduct produced by the separation of air into its various parts. It is included in our atmosphere in tiny, fractional amounts that we inhale with every breath. That Does Not mean you should go out and get a bottle to see if it makes you talk funny (it will), because Xenon shouldn't be inhaled except under the strict supervision of an Anesthetist or Anesthesiologist. Yes indeed, because Xenon has been and (occasionally) is still used in anesthesia, and is even more effective than Nitrous Oxide.
Photo of a Xenon Gas Discharge Tube Courtesy of Wikimedia Commons.