The energy required in ionise a helium atom is equal to `24.6 eV` The energy required to remove both the electron from the helium atom would be

Options

A. 51.8 eV
B. 79 eV
C. 38.2 eV
D. 49.2 eV

Answer

B

Explanation

Ionisation energy in ground state =24.eV
Eneergy required to remove `2^(n)` electron from `He^(2+)`
`" " =Z^(2)(13.6)eV=(2)^(2)(13.6)=54.4eV`
So, total energy required `=24.6+54.4=79eV`