In a radioactive decay series,a radioisotope decays into another radioisotope successively until a stable nucleus is produced.
Th begins a decay series that consists of six alpha decays and four beta decays.What is the final stable isotope produced in this series?

Question

In a radioactive decay series,a radioisotope decays into another radioisotope successively until a stable nucleus is produced. 
Th begins a decay series that consists of six alpha decays and four beta decays.What is the final stable isotope produced in this series?

Quizplus · Accepted Answer

The fact that there are six alpha decays and four beta decays tells us that the decay series involves a total of 10 steps. Thorium-232 (Th-232) undergoes two alpha decays to become radium-228 (Ra-228), which then undergoes four alpha decays to become lead-212 (Pb-212). Pb-212 then undergoes one beta decay to become bismuth-212 (Bi-212), which undergoes three more alpha decays to become thallium-208 (Tl-208). Tl-208 then undergoes one more beta decay to become lead-208 (Pb-208), which is stable. Therefore, the final stable isotope produced in the series is lead-208 (Pb-208).

In a Radioactive Decay Series,a Radioisotope Decays into Another Radioisotope