Parent Nuclide Definition in Physics

Iodine-131 radioisotope
Iodine-131 is the parent nuclide of xenon-131.

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A parent nuclide is a nuclide that decays into a specific daughter nuclide during radioactive decay. A parent nuclide is also known as a parent isotope.


Na-22 decays into Ne-22 by β+ decay. Na-22 is the parent nuclide and Ne-22 is the daughter nuclide. As another example, tellurium-131 is the parent nuclide, which undergoes beta decay to yield the daughter nuclide iodine-131. Iodine-131, in turn, is the parent nuclide of xenon-131.


  • Peh, W. C. G. (1996). "The Discovery of Radioactivity and Radium." Singapore Medical Journal. 37 (6): 627–630.