Question

How do you explain the reactivity of the noble gases in terms of valence electrons?

Answer 1

All of the Noble gases have complete valence shells. I know I am not telling you anything new.

Explanation:

Given a full valence shell, Noble gases, are (i) hard to oxidize, and (ii) hard to reduce. The Noble gases should therefore have a quite limited chemistry, as indeed they do. Nevertheless, even for `He`, some reaction chemistry is known; i.e. `He_2^+` is not something you'll be able to put in a bottle, but it is known spectroscopically.