Calcultte the enrgy required for the process ,
` He^+ (g) rarr He^(2+) (g) + e`
The ionization energy for the H-atom in the grounds state is ` 2. 18 xx 10 ^(-18) J "atom"^(-1)`.

Answer

`E_(1)` for `H` atom `=-1.E.=-2.18xx10^(-18) J`
`E_(1)` for `He^(+)=E_(1(H))xxZ^(2)=-2.18xx10^(-18)xx2^(2)J=-8.72xx10^(-18)J`
The given process represents ionization of `He^(+)`.
The energy required for ionization of `He^(+)=E_(1(He^(+)))=8.72xx10^(-18) J`