Is Cl2 + 2e → 2Cl − Cl2 + 2e → 2Cl− an oxidation half-reaction?
In this example, the chlorine gas (Cl2Cl2) gains two electrons, bringing the oxidation state of 0 to an oxidation state of chloride ions to be -1. The charge here reduced, meaning this is a reduction half-reaction, NOT an oxidation reaction.