The atomic number of fluorine is 9 and its atomic mass is 18.998403.
Its group number is 17 and its period number is 2. It is part of the halogen family. It is a nonmetal and is a gas at normal conditions.
Fluoride is sometimes used as a component in toothpaste.
Fluoride is also sometimes put in drinking water for dental benefits.
Hydro fluoride acid can dissolve glass.