Question

The binding energy of an electron in the ground state of He-atom is $E_0= 24.7e \,V$The energy required to remove both the electrons from the atom is

• A. 24.6e V
• B. 79.0 eV
• C. 54.4 eV
• D. none of these

Answer 1

Answer: (B)

79.0 eV

Answer 2

Given, Energy required to remove electron in ground state from a neutral atom is $24.6 eV$, which makes it $He ^{+}$hydrogen like atom. Energy required to remove electron from singly ionized helium is $13.6 \times 2^{4}$. Therefore, Energy required to remove both the electrons is $24.6+54.4=79.0\, eV$