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

Explanation

For hydrogen like ionthe radius of the nth orbit is
`a_(n)= (n^(2)a_(0))/(2)`
For `Li^(++) ,Z= 3` and in ground state `n = 1` , The radius is
`a_(1) = (53pm)/(3) = 18 pm`