question_answer 1)

Hydrogen resembles halogens in many respects for which several factors are responsible. Of the following factors which one is most important in this respect? (a) Its tendency to lose an electron to form a cation (b) Its tendency to gain a single electron in its valence shell to attain stable electronic configuration (c) Its low negative electron gain enthalpy value (d) Its small size

Answer:

(b) Halogens have the tendency to gain one electron and acquire inert gas configuration. Hydrogen also accepts one electron and acquires helium configuration. \[F\to Ne;\,\,\,\,Cl\to Ar;\,\,\,\,\,Br\to Kr\] \[2{{s}^{2}}2{{p}^{5}}2{{s}^{2}}2{{p}^{6}}\,\,\,3{{s}^{2}}3{{p}^{5}}\,\,3{{s}^{2}}3{{p}^{6}}\,\,4{{s}^{2}}4{{p}^{5}}\,\,4{{s}^{2}}4{{p}^{6}}\]\[\underset{1{{s}^{1}}}{\mathop{H}}\,\to \underset{1{{s}^{2}}}{\mathop{He}}\,\]