The ionisation energy for the Hydrogen atom in the ground state is `2.18 xx 10^(-18)J "atom"^(-1)`. The energy required for the following process `He^(+)(g)rarr He^(2+) (g) +e^(-)` is

Options

A. `8.72 xx 10^(-18)J atom^(-1)`
B. `8.72 xx 10^(-19)J atom^(-1)`
C. `4.35 xx 10^(-18)J atom^(-1)`
D. `2.62 xx 10^(-19)J atom^(-1)`

Answer

A

Explanation

`[IE]_(z) = [IE]_(H) (z^(2))/(n^(2))`