Question

Which of the following species has the negative electron gain enthalpy?

• A. $F^{-}$
• B. $O$
• C. $O^{2-}$
• D. $N{a}^{+}$

Answer 1

The correct option is B $O$

Energy is released when electron is added to $O$ but energy is absorbed in rest of the cases because in all the other cases we are destabilizing the system by adding an electron since they already have a stable electronic configuration.