group 18

The elements of group 18 (formerly called group 0) include the gases helium, neon, argon, krypton, xenon and radon. These elements are known collectively as the inert, or noble, gases, named for their extreme reluctance to combine chemically with other elements. These elements possess the stable electronic configuration of eight electrons (two, in helium's case) in the outermost shell of each inert gases atom, a configuration that most other elements seek by gaining electrons with or losing electrons to their reacting partners. As the atomic number increase, so does the gases ability to form compounds.