A certain radioactive series starts with and ends with . In the overall process, ________ alpha particles and ________ beta particles are emitted.

Question

A certain radioactive series starts with  and ends with  . In the overall process, ________ alpha particles and ________ beta particles are emitted.

Quizplus · Accepted Answer

In a radioactive decay, the number of alpha particles emitted corresponds to the difference in mass number (A) between the parent nucleus and the daughter nucleus, and the number of beta particles emitted corresponds to the difference in atomic number (Z) between the parent and daughter nuclei. 
Looking at the given series, the last four digits of the first and last nucleus differ in the third digit from the end, indicating that there have been 1 beta decay between the parent and daughter nuclei. Also, the second digit from the end of the first and last nucleus has changed from 'e' to 'f', indicating that there have been 1 alpha decay between the parent and the daughter nuclei. We can continue looking at the series in reverse and count the number of alpha and beta decays until we reach the beginning. Doing this, we find that there are a total of 8 alpha decays and 6 beta decays in the overall process. Therefore, the answer is choice C.

A Certain Radioactive Series Starts with and Ends with