What is the ratio of radii of the orbits corresponding to first excited state and ground state in a hydrogen atom?

Explanation

We know that radius of nith orbit in a hydrogen atom is given by
`r_(n) = r_(0)n^(2)`, where `r_(0)` = radius of orbit in stable in stable state corresponding to n = 1 .
`therefore ` radius of hydrogen orbit in first excited state `(n = 2) r_(2) = r_(0) (2)^(2) = 4r_(0)`
`rArr " " (r_(2))/(r_(1)) =(r_(2))/(r_(0)) = (4)/(1)`