The increasing order of electron gain enthalpy of the following substances is: O < S < Se < Te If the order of electron gain enthalpy is correct, enter 1 else 0.

Electron gain enthalpy- It is the amount of energy released when an element accepts an electron.

Lesser the electronic repulsion faced by an electron to get occupied in the outermost shell higher the amount of energy released.

On moving down the group, the electron gain enthalpy decreases from S to Po. Oxygen has low value of electron gain enthalpy.

We know that oxygen is smaller in size than S, so incoming e- on oxygen faces more electronic repulsion on oxygen outermost surface ( due to more e- density).

The increasing order of electron gain enthalpy-

O