The representation is given by writing the anode on left hand side followed by its ion with its molar concentration. It is followed by a salt bridge. Then the cathodic ion with its molar concentration is written and then the cathode.
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.
Anode :
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.
Cathode :
The number of electrons lost must be equal to the number of electrons gained , thus overall equation will be :