question_answer 1)

Which of the following pairs of elements would have a more negative electron gain enthalpy? Explain. (i) O or F (ii) F or Cl

Answer:

(i) F has more negative electron gain enthalpy due to smaller size and greater effective nuclear charge. (ii) The size of fluorine atom is small and thus electron density is high. This resists the addition of electron, hence electron gain enthalpy of fluorine is less negative in comparison to chlorine atom.