A daughter isotope is the product which remains after an original isotope has undergone radioactive decay. The original isotope is termed the parent isotope. A daughter isotope is also known as a daughter product, daughter nuclide, decay product, or radio-daughter.
Example
For example, uranium-238 decays along what is called a decay chain:
238U → 234Th → 234mPa → ... → 206Pb
Uranium-238 is the parent isotope, while thorium-234, protactinium-234m, and lead-206 are all daughter isotopes.
Daughter Isotopes and Half-Life
The half-life of an isotope is used to predict the time half of a sample will decay into a daughter isotope, but it cannot predict when an individual atom will decay into a daughter product. However, the nature of the decay product(s) form is highly predictable.
Sources
- Peh, W. C. G. (1996). "The Discovery of Radioactivity and Radium." Singapore Medical Journal. 37 (6): 627–630.