Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F (ii) F or Cl
(i) O and F are gift withinside the identical length of the periodic table. An F atom has one proton and one electron greater than O and as an electron is being brought to the identical shell, the atomic length of F is smaller than that of O. As F carries one proton extra than O, its nucleus can appeal to the incoming electron extra strongly in assessment to the nucleus of O atom. Also, F desires best one greater electron to gain the strong noble fueloline configuration. Hence, the electron benefit enthalpy of F is greater poor than that of O. (ii) F and Cl belong to the identical institution of the periodic table. The electron advantage enthalpy generally turns into much less bad on transferring down a institution. However, on this case, the price of the electron advantage enthalpy of Cl is greater bad than that of F. This is due to the fact the atomic length of F is smaller than that of Cl. In F, the electron may be introduced to quantum stage n = 2, however in Cl, the electron is delivered to quantum degree n = 3. Therefore, there are much less electron- electron repulsions in Cl and a further electron may be accommodated easily. Hence, the electron advantage enthalpy of Cl is extra bad than that of F.
