Question

The element having high ionization enthalpy but zero election gain enthalpy is ________.

• A. $H$
• B. $F$
• C. $He$
• D. $Be$

Answer 1

The correct option is C $He$

Electronic configuration of ${}_{2}He=1s^2$ which is fully filled outermost shell electronic configuration. The outermost shell of $He$ is $1s$ which can accommodate a maximum of $2e^{-}s$ and hence no extra $e^{-}$ can be added to its' outermost shell. Hence $EGE=0$. Further having high $IE$ due to its' fully filled state.