Find the ratio of `Li^(++)` ions in its ground state assuming Bohr 's model to be vaild

Explanation

For hydrogen -like ions, the radius of the `n^(th)` orbit is `r_(n) =(n^2 r_0)/(Z)`
For `Li^(++), Z=3` and in ground state `n=1`
The radius is `r_(1)=(1^2 xx 53 xx 10^(-12))/(3)m`
`r_(1)=18xx10^(-12)m`.