Which item is a component of a corrosion cell?

• A. A seal
• B. An oxide layer
• C. A cathode, anode, and electrolyte
• D. An insulating barrier

Answer: (C)

A corrosion cell requires three elements to drive the electrochemical reaction: two electrodes that act as the anode and cathode, and an electrolyte that conducts ions to complete the circuit. The anode is where oxidation happens, releasing electrons, while the cathode is where reduction occurs, consuming those electrons. The electrolyte allows ions to move to balance charge as the reaction proceeds, enabling continuous corrosion or its control. A seal doesn’t participate in the electrical or chemical process; it’s just a barrier component. An oxide layer can form on surfaces and influence corrosion behavior, but it’s a surface product rather than a fundamental circuit element. An insulating barrier would prevent current flow and stop corrosion, so it isn’t part of the corrosion cell’s essential components.