Which of the following is an example of oxidation?

• A. Fe → Fe^{2+} + 2e^{-}
• B. Cl_{2} + 2e^{-} → 2Cl^{-}
• C. 2H^{+} + 2e^{-} → H_{2}
• D. Cu^{2+} + 2e^{-} → Cu

Answer: (A)

Verified step by step guidance

1. Understand that oxidation is the loss of electrons by a species, while reduction is the gain of electrons.
2. Look at each reaction and identify whether electrons are being lost or gained by the species on the left side.
3. For the reaction \(\mathrm{Fe \rightarrow Fe^{2+} + 2e^{-}}\), iron (Fe) is losing 2 electrons, which fits the definition of oxidation.
4. For the other reactions, such as \(\mathrm{Cl_{2} + 2e^{-} \rightarrow 2Cl^{-}}\), electrons are being gained, indicating reduction, not oxidation.
5. Therefore, the reaction where electrons are produced on the right side (lost by the species on the left) is the example of oxidation.