• # question_answer 95)   Electronic configuration of some elements is given in column I and their electron gain enthalpies are given in column II. Match the electronic configuration with electron gain enthalpy. Column l Electronic configuration Column ll Electron gain enthalpy/ $\mathbf{kJ}\,\mathbf{mo}{{\mathbf{l}}^{\mathbf{-1}}}$ (1) $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}$ (a) ? 53 (2) $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{1}}$ (b) ? 328 (3) $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}2{{p}^{5}}$ (c) ? 141 (4) $1{{s}^{2}}2{{s}^{2}}2{{p}^{4}}$ (d) + 48

(i - d) Intert gases $(2{{n}^{2}}n{{p}^{6}})$ have positive electron gain enthalpy because addition of electron is not easily possible. (ii - a) Alkali metals have very low electron gain enthalpy. (iii - b) Halogens (chlorine) have very large negative electron gain enthalpy. (iv - c) Oxygen has electron gain enthalpy, next to (chlorine) halogens because oxygen is also an electron deficient element.