Why is the electron gain enthalpy of O or F less than that of S or Cl?

Why is the electron gain enthalpy of oxygen is less than that of sulphur?

Define electron gain enthalpy. How it varies in a group and in a period ? Why is the electron gain enthalpy of O or F is less negative than that of succeeding element in the group ?

Electron gain enthalpy of N is less than that of O. explain.

Give reason for the following. a) The electron gain enthalpy of O is less negative than that of S. b) The size of anion is larger than the parent atom.

" The electron gain enthalpy of "O" is less negative than that of "S" ."

The negative electron gain enthalpy of fluorine is less than that of chlorine.

Explain with reason : The negative electron gain enthalpy of oxygen is less than that of sulphur.