What is the oxidation half-reaction for 2mg+o2

Mg --> Mg²⁺ + 2e

Explanation:

Redox reactions consists of both reduction and oxidation reactions.

one species gets oxidised and other species gets reduced, both reactions happen simultaneously giving rise to a redox reaction.

Oxidation reactions could be either loss of electrons or gain of oxygen.

in oxidation the oxidation number of the species will increase

reduction on the other hand is either gain of electrons or gain of hydrogen.

in reduction the oxidation number of the species will reduce

in this reaction the oxidation half reaction is

Mg --> Mg²⁺ + 2e

Mg is losing electrons therefore its being oxidised

the answer would be a