Which term describes the natural redox process that results in unwanted oxidation of a metal?

• A. Oxidation
• B. Corrosion
• C. Reduction
• D. Electroplating

Answer: (B)

When a metal sits in air and moisture, it can react in a redox couple with the environment. The metal tends to lose electrons (it’s oxidized) while oxygen or water gains electrons (they’re reduced). Over time, this redox process forms oxides and hydroxides on the surface, gradually wearing away the metal. That gradual, unwanted deterioration is what we call corrosion.

Oxidation by itself is just the loss of electrons and doesn’t specify the slow, damaging, environmental context of a metal deteriorating. Reduction is the gain of electrons by another species, which isn’t describing the metal’s deterioration. Electroplating is an intentional, engineered process that uses electricity to deposit a coating, not the natural spoilage of a metal.