Among the noble gases listed—neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe)—xenon (Xe) is generally considered to be the most chemically reactive. This might seem surprising given that noble gases are known for their lack of reactivity, but xenon’s larger atomic size and its ability to form compounds with highly electronegative elements contribute to its reactivity.
The reactivity of noble gases increases down the group in the periodic table due to the increase in atomic size and the corresponding increase in the distance of the outer electrons from the nucleus. Xenon, being the heaviest and largest of these noble gases, possesses a more substantial electron cloud that can be distorted, making it more susceptible to forming bonds with other elements.
In practical terms, xenon can form various compounds, such as xenon fluorides, which are some of the few known compounds of a noble gas. In contrast, neon, argon, and krypton are much less likely to form compounds under normal conditions, as their electron configurations are more stable and less conducive to bonding.