One of these elements is commonly found in the thyroid, while another is the most electronegative.
Two elements from this group are exchanged in an SN2 reaction named for Finklestein. The heaviest of these elements is produced by bombarding bismuth with alpha particles. With a name meaning "salt-formers," this group contains elements in solid, liquid, and gaseous phases at standard temperature and pressure. One of these elements is commonly found in the thyroid, while another is the most electronegative. For 10 points, name this group containing astatine, iodine, fluorine, and chlorine.
Two elements from this group are exchanged in an SN2 reaction named for Finklestein.
{halogens} [or Group 17A; or Group 7]