DAT Bootcamp General Chemistry Practice Test 2026 - Free General Chemistry Practice Questions and Study Guide

Fluorine’s oxidation number is determined by its role as the most electronegative element. In compounds, it almost always pulls electrons toward itself in bonds, so it effectively gains one electron per bond, giving it an oxidation state of −1. The only time it isn’t −1 is when it’s in the elemental form (as F2), where there are no bonds to assign electrons in, so the oxidation number is 0. This is why fluorine is assigned −1 in almost all compounds.