Question

Q-21 Which of the following pair of elements would have a more negative electron gain
enthalpy?

(a) O or F
(b) F or CI
​

Answer 1

Answer:

O or F

Explanation:

Both Oand F are in the 2nd period. From O to F, the atomic size decreases and the effective nuclear charge increases. Both these factors tend to increase the attraction between the nucleus and the incoming electron and hence electron gain enthalpy becomes more negative.