Daughter Isotope Definition - Chemistry Glossary

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.