Inert Gases

The inert, or noble gases are a family of gaseous elements that constitute Group O of the periodic table. Their physical and chemical properties are closely related. The noble gases and their atomic numbers are Helium, Neon, Argon, Krypton, Xenon, and radon. Together they constitute just less than 1% by volume of the atmosphere near the Earth's Surface. The term inert and noble are derived from the extreme reluctance of these gases to combine chemically with other elements. Chemical stability exists because the outmost shell of each noble gas atom is filled with eight electron (octet), except helium, which has two.

Most other chemical elements, when they react has two. Most other chemical element, when they react with one another, do so in order to achieve this stable octet electron configuration either by losing electrons to their reacting partners or by gaining electron from them. Because the noble gases already have the stable electron configuration, they are relatively inert. The ability to form chemical compounds created since 1962 - before which time chemist assumed that inert gases did not form compounds, are XeF₂, XeF₄, and XeO₃. Krypton forms KrF₂, KrF₄, which are stable only at low temperature.