Bromine & chlorine are in a group of elements better known by this name, from the Greek for "salt-forming"
... Fluorine 
and chlorine are gases, iodine is a solid, and bromine is one of only two 
elements .... Fluorine is also used in a polymer commonly known as Teflon, which 
.... salts; hence their name, which comes from two Greek terms meaning "salt-
forming."...