What are the noble gases? The noble gases, also known as group 18 of the periodic table, are comprised of helium, neon, argon, krypton, xenon, and radon. The reason they are called noble is perhaps because of their properties which are fairly pure. They are all gases that are odorless, colorless, and have very low chemical reactivity. They are also very stable elements making it unlikely for them to gain or lose electrons to form bonds with other elements. You could say they are the loners of the periodic table!