(i) The energy associated with the first orbit in the hydrogen atom is `-2.18 xx 10^(18) J atom^(-1) ` what is the energy associated with the fifth orbit ?
(ii) Calculate the radius of Bohr. fifth orbit for hydrogen atom

Explanation

Energy `E_(n) ` of n orbit of 1 electron contaning species
`E_(n) = - 2.18 xx 10^(18) ((z^(2))/( n^(2))) J`
where z= atomic number
n= orbit 1,2,3.
For `lambda` transition occurs in H atom
`(1)/(lambda) = (2.18 xx 10^(18))/( hc ) ((1)/(n_(x)^(2))- (1)/( n_(y)^(2))) 1^(2) = k ((1)/(n_(x)^(2) )- (1)/( n_(y)^(2)))`
So `(1)/(lambda) = k ((3)/(4)) = k ((1)/(n_(x)^(2))- (1)/(n_(y)^(2)))`
if in `n_(x) x=1 ` and `y=2 ` so `((1)/(1^(2))-(1)/(2^(2)))=(3)/(4)`
so wavelength of transition of H `(n_(1) to n_(2))` is equalto transition of `He^(+) (n_(4) to n_(2))`
Lyman series of hydrogen for transition in second to first orbit.