In the reactions below, give the oxidation states (oxidation numbers) of each element indicated in the brackets as a reactant and as a product, and state whether it has been oxidised or reduced. a Agt + CF → AgCl b CO, + 2Mg → 2MgO + C c H2 + F2 → 2HF d CaCO; → CaO + CO2 e 2NO, → N204