Fluorine is the most reactive element on the Periodic Table.
Fluorine has high nuclear charge, and is the most potent oxidant on the Periodic Table. Fluorine chemistry is a specialized branch of inorganic chemistry, and quite a few of the older fluorine chemists bear the marks of this reactivity: i.e. missing eyes, missing fingers.
I found this video on the interwebz introduced by Prof. Martin Poliakoff, a very distinguished inorganic chemist. Because he too respects the reactivity of fluorine, he lets a a specialist professor (who has all his fingers and eyes) perform the demonstration: