Any of the six nonmetallic elements that are present in Group 17 in the periodic table are considered halogens.
Fluorine (), chlorine (), bromine (), iodine (), astatine (), and tennessine are the halogen elements ().
The free halogen elements are not found in nature due to their high reactivity. Fluorine is the most common halogen in combined form in the Earth's crust.
Uses of halogens:
Chlorine is frequently used to purify water and in a variety of chemical reactions.
The most common use of iodine is as an antiseptic.
Both fumigants and insecticides, as well as photographic films, are made from bromine.