The pole where corrosion residue builds up is known as what?

The correct answer identifies the pole where corrosion residue builds up as the cathode. In electrochemical cells, the cathode is the electrode where reduction occurs; it attracts cations from the solution and can accumulate corrosion products due to the reaction taking place.

At the cathode, electrons are supplied, reducing metal cations to their metallic state, which may lead to the buildup of metal oxides or other corrosion byproducts over time. This process is a result of the electrochemical actions within the system where the cathode serves as a site for these reactions.

Understanding the roles of each component in electrochemistry is crucial. The anode, conversely, is where oxidation occurs and represents a site of metal loss rather than accumulation. The term "residue point" is not standard terminology in this context and does not specifically relate to the processes that occur at the cathode.