Step-by-step explanation:
First Reaction;
Ca + ZnCl2 --> CaCl2 + Zn
Oxidized Reactant: Ca. There is increase in oxidation number from 0 to +2
Reduced Reactant: Zn. There is decrease in oxidation number form +2 to 0
Second Reaction:
FeI2 + Mg --> Fe + MgI2
Oxidized Reactant: Mg. There is increase in oxidation number from 0 to +2
Reduced Reactant: Fe. There is decrease in oxidation number form +2 to 0
Third Reaction;
Mg + 2AgNO3 --> Mg(NO3)2 + Ag
Oxidized Reactant: Mg. There is increase in oxidation number from 0 to +2
Reduced Reactant: Ag. There is decrease in oxidation number form +1 to 0