Question: The radius of the second Bohr orbit, in terms of the Bohr radius, $\mathrm{a}_{0}$, in $\mathrm{Li}^{2+}$ is :
$\frac{4 \mathrm{a}_{0}}{9}$
$\frac{2 a_{0}}{9}$
$\frac{2 \mathrm{a}_{0}}{3}$
$\frac{4 \mathrm{a}_{0}}{3}$
Correct Option: , 4
Solution:
