The first ΔiH1 and second  ΔiH2 ionisation enthalpies (in kJmol−1) and the electron gain enthalpy  ΔegH (in kJmol−1) of the elements  I. II, III, IV and V are given below Element      ΔiH1  ΔiH2  Δeg HI     5207300−60II    4193051−48III  16813374−328IV  10081846−295v    23725251+48The most reactive metal and the least reactive non-metal of these are respectively