Fluorine
F
The atomic number is 9 and the atomic mass is 18.998. It's period number is 2 and its group number is 17. The group name is Halogen. It is a gas and it is a nonmetal. Fluorine is used toothpaste, drinking water, and etching solutions.
Toothpaste
We use toothpaste to brush our teeth. It cleans our teeth, makes them whiter, and prevents cavities.
Drinking water
Drinking water is tap water but the water is ran through carbon filters to remove chlorine. Fluorine is put in the water to prevent cavities.
Etching glass
Artist use fluorine in glass to create designs on glass.