Xenon hexa­fluor­ide

XeF₆

16/50 common

Although the defining chemical feature of the noble gases is their unreactivity, the heavier members of this group (particularly krypton and xenon) are indeed capable of forming simple compounds upon reaction with sufficiently oxidizing species. This is because, although all noble gases possess a full octet in their neutral monatomic state, the valence electrons for heavier noble gases are sufficiently shielded and distanced from the nucleus that they may be abstracted by electron-hungry elements such as fluorine and oxygen. Xenon hexafluoride is produced by the reaction of xenon with fluorine gas and is a powerful fluorinating agent — so much so that it is scarcely used in synthesis, as its fluorinating power is essentially overkill compared to its comparatively milder siblings XeF₄ and XeF₂.