Question

Calculate the energy required for the process:
$H{e}^{+}\left(g\right)\to H{e}^{2+}\left(g\right)+e^{-}$

If the ionisation energy for the H atom in the ground state is $2.18\times {10}^{-18}$ J/atom.

Answer 1

He${}^{+}$ resembles H because both have single electron and He${}^{+2}$ resembles H${}^{+}$ . The energy for He${}^{+2}$ formation from He${}^{+}$ equals to ionisation energy of 'H' = 2.18 × 10${}^{-18}$ J/atom.

H(g) $\to$ H${}^{+}$ (g) +e I.e=2.18 × 10${}^{-18}$ J/atom. As both have same no. of electrons.