Carbon-14
archaeological dating
Cobalt-60
cancer therapy
Iodine-131
Thyroid therapy
Potassium-40
Geological dating
Phosphorus-32
Leukemia treatment
Technetium-99m
organ imaging
gall bladder function, detect internal bleeding
Uranium-235
nuclear reactors
Xenon-133
lung function
Iridium-192
breast cancer
Thallium-201
heart function