Question

The radius of germanium ( $Ge$ ) nuclide is measured to be twice the radius of ${}_4^9\text{Be}\text{.}$ Calculate the number of nucleons in $Ge$ .

Answer 1

Answer: 72

Nuclear radius, $R=R_0(A$,
or $R\propto (A$
$\frac{R_{Be}}{R_{Ge}}=\frac{(9{)}^{1/3}}{(A{)}^{1/3}}$ or, $\frac{R_{Be}}{2R_{Be}}=\frac{(9{)}^{1/3}}{(A{)}^{1/3}}(\because$ Given $R_{Ge}=2R_{Be})$
or $(A=2\times (9$
or $A=2^3\times 9=8\times 9=72$
$\therefore$ The number of nucleons in $Ge$ is 72 .