iodine-131

iodine–131

noun \-ˌwən-ˌthərt-ē-ˈwən\

Definition of IODINE-131

: a heavy radioactive isotope of iodine that has the mass number 131 and a half-life of eight days, emits beta particles and gamma rays, and is used especially in the form of its sodium salt in the diagnosis of thyroid disease and the treatment of goiter