The ionisation enrgy of H-atom is ` 13. 6 eV`. What will be ionisation energy ofg ` He^(2+)`. Ions ?

Explanation

We know,
` E_1 " for " He^+ = E_1 " or " H xx z^2`
` = 13 . 6 xx 4 = 54 .4 eV`
` E_1 " for " Li^(2+) = E_1 "or " H xx Z^2`
` = 13 .6 xx 9= 122 . 4 eV`.