Question

Find ratio of radius of `2^(nd)` orbit of `He^(+)` ion `& 3^(rd)` orbit of `Be^(+3)` ion.

Answer 1

`r_(1)` (radius of `2^(nd)` orbit of `He^(+)` ion)= `0.529(2^(2)/2)Å`
`r_(2)` (radius of `3^(rd)` orbit of `Be^(+++)` ion)= `0.529(3^(2)/4)Å`
Therefore `r_(1)/r_(2)=(0.529xx2^(2)//2)/(0.529xx3^(2)//4)=8/9`