The term ONE OF THE HALOGENS can be solved by two crossword solutions, BROMINE (7 letters) and IODINE (6 letters). BROMINE is a chemical element with the symbol Br and atomic number 35. It is a member of the halogen group in the periodic table and is a fuming red-brown liquid at room temperature. Iodine is a chemical element with the symbol I and atomic number 53. It is a member of the halogen group in the periodic table and is a lustrous, purple-black solid at room temperature.