Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F (ii)F or Cl (iii) O or S. Give reason to support your answer.

Which of the following pairs of elements would have a more negative el

1.	Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F (ii)F or Cl (iii) O or S. Give reason to support your answer.
Answer» O or F.Explanation: ELECTRON gain enthalpy of F is much more negative than that of O. This is because as we from O to F, the atomic size decreases and nuclear CHARGE increases, thereby increase the attraction of the nucleus for the incoming electron and hence electron gain enthalpy BECOMES more negative.