What elements are halogens?

In oxidizing another element, a halogen is itself reduced; i.e., the oxidation number 0 of the free element is reduced to −1. The halogens can combine with other elements to form compounds known as halides—namely, fluorides, chlorides, bromides, iodides, and astatides. read more

The halogens are a group of elements on the periodic table. It is the only element group that includes elements capable of existing in three of the four main states of matter at room temperature (solids, liquid, gas). read more

The halogens are five non-metallic elements found in group 17 of the periodic table. The term "halogen" means "salt-former" and compounds containing halogens are called "salts". All halogens have 7 electrons in their outer shells, giving them an oxidation number of -1. read more