(a) Complete the following chemical reaction equation :(i)MnO_(4(aq))^(-)+C_(2)O_(4(aq))^(2-)+H_(aq)^(+) to (ii) Cr_(2)O_(7(aq))^(2-)+Fe_((aq))+H_((aq))^+to (b) Explain the following observation about the transition /inner transition elements: (i) There is in general an increase in density of element from titanium (Z=22) to copper (Z=29) (ii) there occurs much more frequent metal bonding in compounds of heavy transition elements (3^(rd) series) (iii) The members of the actinoid series exhibit a larger number of oxidation states than the corresponding members of the lanthanoid series (a) Complete the following chemical equation for reaction: (i) 8MnO_(4)^(-)+H_(2)O+3S_(2)O_(3)^(2-) to (ii) Cr_(2)O_(7)^(2-)+3H_(2)S+8H^(+) to (b) Give an explanation for each of the following observations: (i) The gradual decrease in size (actinoid contractions) from element to element is greater among the actinoids than among the lanthanoids (lanthanoid contraction). (ii) The greatest number of oxidation states are exhibited by the members in the middle of a transition series. (iii) With the same d-orbital configuration (d^(4) Cr^(2+)) ion is a reducing agent but Mn^(3+) ion is an oxidising agent.