Question

Ratio of nuclear radii of ${\text{Cs}}^{135}$ to ${\text{Ca}}^{40}$ is-

• A. $7:5$
• B. $3:2$
• C. $9:5$
• D. $9:2$

Answer 1

The correct option is B $3:2$

We know, $R=R_0{A}^{\frac{1}{3}}$

$\Rightarrow \frac{R_1}{R_2}={\left(\frac{A_1}{A_2}\right)}^{\frac{1}{3}}={\left(\frac{135}{40}\right)}^{\frac{1}{3}}$

$={\left(\frac{27}{8}\right)}^{\frac{1}{3}}={\left(\frac{3^3}{2^3}\right)}^{\frac{1}{3}}$

$\therefore \frac{R_1}{R_2}=\frac{3}{2}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(B\right)$ is the correct answer.