The energy of second orbit of hydrogen is equal to the energy of ,

Options

A. Fourth orbit of `He^+`
B. Fourth orbit of `Li^(2 +)`
C. Second orbit of `He^+`
D. Second orbit of `L i^(2 +)`.

Answer

A

Explanation

(a) `E = - (Z^2)/(n^2) xx 13.6 eV`
`E_2 = - (13.6)/(4) "for" 'H'`
`E = -(Z^2)/(n^2) xx 13.6 eV`
`- (13.6)/(4) = - (Z^2)/(n^2) xx 13.6`
`(Z^2)/(n^2) = (1)/(4) (Z = 2, n = 4)]`.