(i) \\\\(\\displaystyle I_2 < F_2 < Br_2 < Cl_2\\\\) The electron affinity of Chlorine is maximum in the periodic table and so the bond dissociation enthalpy. Flourine has lower bond dissociation enthalpy than \\\\(Br_2\\\\) and \\\\(Cl_2\\\\). Due to small size electronic repulsion is very high. \\\\(I_2\\\\) has lowest bond dissociation enthalpy due to quite larger size it is easiest to break the bond.(ii) \\\\(\\displaystyle HF < HCl < HBr < HI \\Rightarrow\\\\)Acidic strength of Halogen acids increases down the group.(iii) \\\\(\\displaystyle BiH_3 < SbH_3 < AsH_3 < PH_3 < NH_3\\Rightarrow\\\\) Basic strength decreases down the group because as we go down the group the size of the atom and thus the electron density decreases. These compounds are lewis base having 1 lone pair on the central atoms. As the electron density decrease the tendency to donate electron pair decreases.