fluorine is the most reactive nonmetal. to fluorines immediate right in the periodic table is neon, a noble gas that does not form chemical bonds. explain this contrast in reactivity in terms of atomic structure

Neon is a noble gas which means it has 8 valence electrons. An electron becomes stable and inert when it has 8 valence electrons.

Fluorine has 7 electrons and needs 1 more to become stable. This makes Fluorine highly reactive compared to Neon, which is already stable.