Final answer:
A good oxidizing agent is one that gains electrons easily during a chemical reaction, causing another substance to be oxidized while it gets reduced itself.
Step-by-step explanation:
What makes something a good oxidizing agent? The answer is a) Gaining electrons easily. A good oxidizing agent is a substance that causes oxidation by accepting electrons and, in the process, itself gets reduced. An example of a strong oxidizing agent is fluorine (F2), which can readily oxidize other substances by gaining electrons. For instance, in the reaction where fluorine oxidizes gold metal, the fluorine is reduced as it gains electrons from the gold. Another example is oxygen, which is a commonly known oxidizing agent that gains electrons to go from the 0 oxidation state to the 2- state.