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 `Li^(2+)`.

Answer

A

Explanation

`E=-(Z^(2))/(n^(2))xx13.6eV`
`E_(2)=-(13.6)/(4)` for `H`
`E=-(Z^(2))/(n^(2))xx13.6` eV
`-(13.6)/(4)=-(Z^(2))/(n^(2))xx13.6`
`(Z^(2))/(n^(2))=(1)/(4)(Z=1,n=2)`.