Q. $N^{\text {th }}$ level of $Li ^{2+}$ has the same energy as the ground state energy of the hydrogen atom. If $r_{N}$ and $r_{1}$ be the radius of the $N^{\text {th }}$ Bohr orbit of $Li ^{2+}$ and first orbit radius of $H$ atom, respectively, then the ratio $\frac{r_{N}}{r_{1}}$ is
Atoms
Solution: