The octet rule states that if the octet of an atom is complete, meaning it has 8 electrons in its valence shell, then it will not react. Xenon in xenon fluoride does not obey the octet rule because the valence shell of xenon in xenon fluoride contains 10 electrons, instead of 8. Xenon is an inert gas because its octet is already complete, which means this reaction does not take place under normal conditions.