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 ompletelyis:

Options

A. 34 eV
B. 20 eV
C. 79eV
D. 109 eV

Answer

C

Explanation

Let energy required to remove an electron from He-atom be x eV.
Energy required to remove an electron from hydrogen atom is 13.6 eV , hence energy required to remove electron from singly ionised He-atom should be `Z^2` times hence `(2)^2` times which is =4 x 13.6 =54.4 eV
Given : 54.4 eV = 2.2x `rArr` x=24.73 eV
Total energy required to ionise helium atom =54.4 eV+24.73 eV = 79.13 eV