Calculate the energy 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)`.

Explanation

Energy associated with hydrogen-like species is given by,
`E_(a) = -2.18 xx 10^(-18) ((Z^(2))/(n^(2))) J`
For ground state of hydrogen atom,
`Delta E = E_(oo) - E_(1)`
= `0 - [-2.18 xx 10^(-18) {((1)^(2))/((1)^(2)) }]J`
`Delta E = 2.18 xx 10^(-18) J`
For the given process ,
`He_((g))^(+) to He_((g))^(2+) + e^(-)`
An electron is removed from n = 1 to n = `oo`
`Delta E = E_(oo) - E_(1)`
= `0 - [-2.18 xx 10^(-18) {((2)^(2))/((1)^(2)) }]`
`Delta E = 8.72 xx 10^(-18) J`
`therefore` The energy required for the process is `8.72 xx 10^(-18) J`.