Fluorine has an atomic number of 9; its chemical symbol is F. It is the lightest element in the halogen column and has one isotope, fluorine-19. It is a group 17 element. It is a non-metal. It is extremely reactive with both organic and inorganic substances. In Earth's crust, it is the 13th most abundant element and at standard pressure and temperature, it is a pale yellow gas. Its name is derived from the Latin fluo, meaning flow. The mineral fluorite was added to metal ores to lower their melting points in the process of smelting. In 1811, it was named fluorine after the mineral fluorite, from which it is derived. In 1886, Henri Moissan used electrolysis to isolate the element fluorine. During WWII, fluorine was used for uranium enrichment for the Manhattan Project, which produced the first atomic bomb.