<u>Answer:</u> Magnesium is getting oxidized and is the reducing agent. Chlorine is getting reduced and is the oxidizing agent.
<u>Explanation:</u>
Oxidation reaction is defined as the chemical reaction in which an atom looses its electrons. Here, the oxidation state of atom increases.
Reduction reaction is defined as the chemical reaction in which an atom gains electrons. Here, the oxidation state of atom decreases.
Oxidizing agents are defined as the agents which help the other substance to get oxidized and itself gets reduced. These undergo reduction reactions.
Reducing agents are defined as the agents which help the other substance to get reduced and itself gets oxidized. These undergo oxidation reactions.
For the given chemical equation:
<u>Oxidation half reaction:</u>
As, magnesium is loosing 2 electrons and its oxidation state is getting increased. Thus, it is undergoing oxidation reaction and is considered as reducing agent.
<u>Reduction half reaction:</u>
As, chlorine is gaining 2 electrons and its oxidation state is getting reduced. Thus, it is undergoing reduction reaction and is considered as oxidizing agent.