Question

The surface area of a nucleus varies with mass number $A$ as

• A. $A^{2/3}$
• B. $A^{1/3}$
• C. $A$
• D. $Constant$

Answer 1

Answer: (A)

$A^{2/3}$

$\begin{array}{cc}& R=R_0{A}^{1/3}\\ \therefore \text{Radius,}& R\propto A^{\prime /3}\end{array}$

$\begin{array}{c}\text{Surface Area}=4\pi R^2\\ \therefore S\cdot A\propto R^2\\ \therefore \text{Surface Area is proportional to}{A}^{2/3}\end{array}$