Technetium-99m is a widely used radioactive tracer isotope in Nuclear Medicine. ...Technetium -99m is produced by bombarding molybdenum 98Mo with neutrons. The resultant 99Mo decays with a half-life of 66 hours to the metastable state of Tc . This process permits the production of 99mTc for medical purposes. Since 99Mo is a fission product of 235U fission, it can be separated from the other fission products and used to generate 99mTc. For medical purposes, the 99mTc is used in the form of pertechnate, TcO4-