Symbol

F

Atomic Number

9

Atomic Mass

18.998404

Family

Group 17 (Viia) Halogen Pronunciation

FLOR-een

Overview

Fluorine is the lightest member of the halogen family, elements in Group 17 (VIIA) of the periodic table. The periodic table is a chart that shows how elements are related to one another. These include chlorine, bromine, iodine, and astatine. Fluorine is the most active chemical element, reacting with virtually every element. It even reacts with the noble gases at high temperatures and pressures. The noble gases, or Group 18 (VIIIA), also known as the inert gases, generally do not react with other elements.

Fluorine was discovered in 1886 by French chemist Henri Moissan (1852-1907). Moissan collected the gas by passing an electric current through one of its compounds, hydrogen fluoride (H₂F₂).

Consumers are most familiar with fluorine's use in two products. Fluorine gas is used to make fluorides, compounds that were made part of toothpastes in...