Because xenon is a tracer for two parent isotopes, Xe isotope ratios in meteorites are a powerful tool for studying the formation of the solar system.

NRU actually produces the more stable parent isotope, molybdenum-99, which is shipped to medical labs.

Detection was by spontaneous fission of the claimed parent isotope with half-life of 5 minutes.

The following table lists some of the most important radiogenic isotope systems used in geology, in order of decreasing half-life of the radioactive parent isotope.

Plutonium-241 is the parent isotope of the neptunium decay series, decaying to americium-241 via β or electron emission.

For rocks dating back to the beginning of the solar system, this requires extremely long-lived parent isotopes, making measurement of such rocks' exact ages imprecise.

Though Y has the short half-life, it exists in secular equilibrium with its long-lived parent isotope, strontium-90 (Sr) with a half-life of 29 years.

The parent isotope of indium-111 is tin-111, with a decay mode of electron capture.

A parent isotope is one that undergoes decay to form a daughter isotope.

With the progress of time, the final decay product accumulates as the parent isotope decays at a constant rate.