Explain in brief for the following: (i) Anions are bigger in size than their parent atom. (ii) Oxygen has lesser first ionization enthalpy than nitrogen (iii) Fluorine has less negative electron gain enthalpy than chlorine
(i) Anions are formed when a neutral atom gains one or more electrons. Since the number of electrons increases and the number of protons remains same, the effective nuclear charge decreases which results in decreases in ionic radii. (ii) Due to the half-filled orbital nitrogen 1s2 2s2 2p3, the stability of this configuration is more and ionization energy is higher than oxygen. (iii) Due to the smaller size and seven electrons in its outermost shell, incoming electrons experience less attraction in F. hence less energy will be released in case of F than Cl.
