Which statement BEST describes the process of oxidation?

Analyze the question: You are asked which statement best describes oxidation. The options mix up the definitions of oxidation and reduction, so you need to know which is which.

Concept: Oxidation can be defined in several ways, and reduction is the exact opposite of each:

| Oxidation | Reduction | |---|---| | Loss of electrons | Gain of electrons | | Gain of oxygen | Loss of oxygen | | Loss of hydrogen | Gain of hydrogen | | Increase in oxidation number | Decrease in oxidation number |

The electron definition is the most fundamental and works for all redox reactions, including those with no oxygen or hydrogen.

Checking each option:

• A. Addition of hydrogen: This is reduction, not oxidation.
• B. Loss of oxygen: This is reduction.
• C. Decrease in oxidation number: This is reduction.
• D. Loss of electrons: This is oxidation. ✔
• E. Gain of electrons: This is reduction.

Example: Mg → Mg²⁺ + 2e⁻. Magnesium loses electrons and its oxidation number rises from 0 to +2, so it is oxidised.

Answer: The correct option is D, loss of electrons.

Tip: Remember OIL RIG: Oxidation Is Loss (of electrons), Reduction Is Gain. Any option that says "gain of electrons", "decrease in oxidation number", "loss of oxygen" or "addition of hydrogen" points to reduction.