Corrosion occurs when there is a _____ differential between two components of a system.

Corrosion is fundamentally linked to electrochemical processes, which are influenced by voltage differentials between two components in a system. When there is a voltage differential, it can result in a flow of electrons from anode to cathode, creating a scenario conducive to corrosion. This occurs in many environments where metals are exposed to electrolytes, leading to anodic dissolution and the consequent degradation of the material.

In contrast, current refers to the flow of electric charge resulting from a potential difference, and while it plays a role in the corrosion process, the root cause initiating corrosion is the voltage difference. Supply does not directly relate to the driving forces of corrosion, as it may refer to the provision of materials or energy but does not inherently cause corrosion. Similarly, pH can impact the rate of corrosion by influencing the aggressiveness of the electrolyte but does not denote a differential specifically. Thus, the voltage differential is critical in understanding and predicting corrosion behavior in various systems.