Question

Let binding energy per nucleon of nucleus be denoted by \(E_{bn}\) and radius of nucleus be denoted as \(r\). If mass number of nuclei A and B are 64 and 125 respectively then:

• A. \(r_A
• B. \(r_A>r_B,\;E_{bnA}>E_{bnB}\)
• C. \(r_A=r_B,\;E_{bnA}
• D. \(r_AE_{bnB}\)

Hint:

Medium mass nuclei are most stable.

Answer 1

The Correct Option is D

Step 1: Nuclear radius:
\[ r \propto A^{1/3} \Rightarrow r_A < r_B \]

Step 2: Binding energy per nucleon peaks near \(A \approx 56\).

Step 3: Hence nucleus with \(A = 64\) has higher \(E_{bn}\) than \(A = 125\).