Give reactions for the following statements:
(a) Transition elements and their compounds acts as a good catalyst.
(b)  ${\mathrm{E}}_{\left({\mathrm{Mn}}^{2+}/\mathrm{Mn}\right)}^0$ value is highly negative as compared to other elements.
(c) Cr⁺²   is a strong reducing agent.

(a) Since transition metals exhibit various oxidation states and also they have tendency to adsorb on the surface and activate them in the process.

(b) Since the d subshell is half filled , the value is higher compare to other elements.

(c) Cr+2 acts as strong reducing agent because when it looses on electron and becomes Cr+3 it becomes  more stable as it has half filled t2g orbitals.