Question

If E1 and E2 are the binding energy per nucleon for the parent nuclei and its daughter

nuclei, then

A) E1 > E2 B) E1 = E2 C) E1 < E2 D) E1 = 3E2​

Answer 1

answer : option (c) E1 < E2

explanation : parent nuclei : nucleus present before decay is known as parent nuclei.

daughter nuclei : resultant nucleus or nuclei from decay process is known as daughter nuclei.

in alpha decay process ....

$\textbf{parent}\rightarrow\textbf{daughter}+\textbf{alpha-particle}$

here you can see that number of nucleons in case of daughter nuclei is less than parent nuclei.

if we assume number of nucleons in parent nuclei is A

then, number of nucleons in daughter nuclei is (A - 4)

here obviously , E/(A - 4) > E'/A , where E is binding energy of daughter nuclei and E' is binding energy of parent. but here you should noticed that decay process happens to get stability of nuclei. so, daughter nuclei is more stable than parent nuclei that's why, E/(A - 4) > E'/A

so, E2 > E1

hence, option (c) is correct.