Question

Which stable nuclei have a diameter of 7.46 fm?

Short answer

Therefore, chemical element who has stable isotope of A = 30 is silicon Si.

Step-by-step solution

Given information

$$\begin{gathered} r=7.46\mathrm{fm}\to 7.46\times {10}^{-15}\mathrm{m} \\ {\mathrm{r}}_{\mathrm{o}}=1.2\mathrm{fm}\to 1.2\times {10}^{-15}\mathrm{m} \end{gathered}$$

Explanation

We have to find value of A from next formula:

$$\begin{gathered} r=2r_o{A}^{1/3} \\ {A}^{1/3}=\frac{r}{2r_o} \\ A={\left(\frac{7.46\mathrm{fm}}{2·(1.2\mathrm{fm})}\right)}^3 \\ A={\left(\frac{7.46\mathrm{fm}}{2.4\mathrm{fm}}\right)}^3 \\ A=(3.108{)}^3 \\ A=30 \end{gathered}$$

Chemical element who has stable isotope of A = 30 is silicon Si.