By what unit the oxidation number changes for underline elements in the following reaction-
Zn + HNO3 → NH4NO3 + Zn (NO3)2 + H2O
(A): Transition metals can act as catalysts because these can change their oxidation state. How does Fe(III) catalyse the reaction between iodide and persulphate ions?
(B): Mention any three processes where transition metals act as catalysts.