a corrosive pale yellow or brown gasthat
is a powerfuloxidizingagent.
It is the most reactive and most electronegative of all the elements on the
classic Pauling scale(4.0), and
readily forms compounds with most other elements. It is found in the -1oxidation
state, except when bonded to another fluorine in F2which
gives it an oxidation number of 0. Fluorine combines with thenoble
andradon. Even in dark, cool
conditions, fluorine reacts explosively withhydrogen.
The reaction with hydrogen can occur at extremely low temperatures, using liquid
hydrogen and solid fluorine. It is so reactive that metals,water,
as well as most othersubstances,
burn with a bright flame in a jet of fluorine gas. In moist air, it reacts with
water to form the also dangerous hydrofluoric acid.