A radionuclide, or a radioactive nuclide, is an atom with an unstable nucleus, characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or via internal conversion. During this process, the radionuclide is said to undergo radioactive decay, resulting in the emission of gamma ray(s) and/or subatomic particles such as alpha or beta particles.

Bone-seeking radionuclides for therapy
Microbial reduction of metals and radionuclides
Report of the Radionuclides in Nephrourology Committee on renal clearance.
Phytoremediation of metals, metalloids, and radionuclides
Production of selected cosmogenic radionuclides by muons: 2. Capture of negative muons
Handbook for the Assessment of Soil Erosion and Sedimentation Using Environmental Radionuclides
Handbook for the Assessment of Soil Erosion and Sedimentation Using Environmental Radionuclides
Age-dependent doses to members of the public from intake of radionuclides: Part 5. Compilation of ingestion and inhalation dose coef...
Comparison of somatostatin analog and meta-iodobenzylguanidine radionuclides in the diagnosis and localization of advanced neuroendo...
Age-dependent doses to members of the public from intake of radionuclides: Part 2. Ingestion dose coefficients. A report of a Task G...