Q.
The energy required to remove the electron from a singly ionized Helium atom is 2.2 times the energy required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is :
Energy required to remove electron from a singly ionised Helium atom is given as E=n213.6Z2=(1)213.6(2)2 =13.6×4=54.4eV
Let energy required to remove an electron from Helium atom is E′.
It is given E=2.2E′. Therefore, E′=2.2E=2.254.4eV=24.7eV
Thus, total energy required to ionise the Helium atom completely is E+E′=54.4eV+24.7eV=79.1eV∼79eV