Which element is a halogen? argon bromine calcium lithium?

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. The halogens exist, at room temperature, in all three states of matter:

Solid - Iodine,

Astatine Liquid - Bromine

Gas - Fluorine, Chlorine

Answer is bromine