Question

The binding energy of an electron in the gorund state of He atom is equal to `E_0 = 24.6 eV.` Find the energy required to remove both electrons form the atom.

Answer 1

Energy required to remove first electron is
24.6 eV. After removing first electron form this
atom, it will become `He^+`
`E_1 =- (13.6)(2)^2 (as E prop Z^2 and Z=2)`
= - 54.4 eV
`:. Energy required to remove this second electron
will be 54.4 eV.`
`:. Total energy required to remove both electrons`
=24.6 +54.4
=79 eV.