Calculate the energy required for the process.
`He_(g)^(+) rarr He_((g))^(2+) + e^(-)`
The ionisation energy for the H atom in its ground state is `-13.6 eV atom^(-1)`.

Explanation

The ionization energy for the H atom in its ground state `= -13.6 eV "atom"^(-1)`
Ionization energy = `(-13.6)/(n^2) z^2 eV`
Z = atomic number
n = Principle quantum number or shell number
For `He n = 1, Z = 2`
I.E = `(-13.6 xx 2^2)/(1^2) eV`
I.E of the `He^(2+) = -54.4 eV`.