Question

Which of the following statement(s) is/(are) correct?

• A. The electron affinity for Sulphur is more exothermic than that for Oxygen
• B. Successive ionization energies of an atom always increase.
• C. First ionization energy of $N$ is greater than that of $O$
• D. Chlorine has larger atomic size as well as electron afinity than that of fluorine.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A The electron affinity for Sulphur is more exothermic than that for Oxygen
B Successive ionization energies of an atom always increase.
C First ionization energy of $N$ is greater than that of $O$
D Chlorine has larger atomic size as well as electron afinity than that of fluorine.

(A) Oxygen being smaller in size than sulpfur, has its valence shell electrons placed more closely than sulpfur. Oxygen experiences more inter electronic repulsion than that of sulphur. So, electron affinity of sulphur is more exothermic than that of oxygen.
(B) As the charge increases, the size decreases as the effective nuclear charge increases. So valence shell electron gradually becomes more tightly held by the nucleus.
(C) Valence shell electronic confuguration of $N$ is $n{s}^{2}n{p}^3$ (half filled stable configuration).

(D) Down the group atomic size increases. Flourine experiences more inter electronic repulsion than that of Chlorine. So, Fluorine has less electron affinity than that of Chlorine.