Question

An energy of `24.6 eV` is required to remove one of that electrons from a neutal helium atom. The enegy (in `eV`)required to remove both the electrons from a netural helium atom is
A. `38.2`
B. `49.2`
C. `51.8`
D. `79.0`

Answer 1

Correct Answer - D
After removing one electron `He^(+)` become hydrogen like and energy required to remove the second
` =0-((-13.6xxZ^(2))/n^(2))=13.6xx4=54.4eV`
`therefore` energyrequired to remove both the electerons" =24.6+54.4=79.0eV`