How would you account for the fact that the transition metals and their compounds are found to be good catalysts in many processes?

Answer

According to activated complex theory (intermediate compound formation theory), the catalyst combines with the reactant//s to form an intermediate (an unstable species called activated complex which finally decomposes to form the products regenerating the catalyst
`underset"Reactant"(A)+underset"catalyst"(C) to underset("intermediate")underset("Activated Complex")([AC])to underset"Product"(B)+underset"Catalyst"(C)`
The reaction proceeds through a new path with lower surface area with free valencies on which the reactants are adsorbed. As a result, the concentration of the reatants on the surface increases and hence the rate increasees. larger surface area with free valancies on which the reactants