Halogens make a group of nonmetal chemical elements from group 17. The group of halogens is the only periodic table group which contains elements in all three familiar states of matter at standard temperature and pressure. The five halogens that occur naturally are fluorine (F), chlorine (Cl), bromine (Br), Iodine (I) and the radioactive astatine (At). The synthetic element 117, ununseptium may also be a halogen.
The transuranic elements below are predicted to be halogens.