The energy of the electron in the first orbit of `He^+` is `- 871.6 xx 10^-20 J`. The energy of the electron in the first orbit of hydrogen would be.

Options

A. `- 871.6 xx 10^-20 J`
B. `- 435.8 xx 10^-20 J`
C. `- 217.9 xx 10^-20 J`
D. `- 108.9 xx 10^-20 J`

Answer

C

Explanation

( c) `E_(1 He^+) = E_(1 H) xx z^2`
`- 871 xx 10^-20 = E_(1 H) xx 4`
`E_(1 H) = - 217.9 xx 10^-20 J`.