Fluorine is an element of many mosts: It is the most reactive of all of the elements, the most powerful oxidizing agent, and the most electronegative. But its true strength and the secret of its success lies in the compounds it forms--some of the most stable and inert substances known to man. These compounds have enabled a steady stream of scientific and commercial advances: Staying warm and dry in a downpour, cooking with the ease of a nonstick pan, and beaming a "cavity free" smile are all available thanks to the fluorine atom.