fluorine
n. uncountablen. a very active, greenish-yellow gas that is the most reactive of all the chemical elements. It is used to make things like toothpaste and plastic.
n. a highly reactive, pale yellow-green diatomic gas with the atomic number 9. It is the most electronegative and reactive of all the chemical elements, typically existing in a gaseous state at standard temperature and pressure.
Fluorine is used to make certain types of plastic.
The chemist handled the fluorine gas with extreme care because it reacts violently with almost any other substance.
As the lightest halogen, fluorine exhibits unique properties that make it essential for the synthesis of pharmaceuticals and high-performance materials, though its extreme reactivity requires specialized containment.
From Latin fluor (“flow”) + -ine. Coined by British chemist Humphry Davy in 1813.