. 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 

A. 20 eV

B. 34 eV 

C. 79 eV

D. 109 eV 

Best Answer

Ans: C

Sol :Energy required to remove e from singly ionized helium atom = 54.4 eV 

Let energy required to remove e form helium atom = N eV 
From the question, 
54.4 eV = 2.2×N 
∴ N = 24.72 eV 
Energy required to ionize helium atom 

(54.4 + 24.72) = 79.12 eV


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