Which metals are most susceptible to uniform surface corrosion?

The correct choice is magnesium and low alloy steels because these materials are known for their susceptibility to uniform surface corrosion, particularly in environments that are conducive to corrosion, such as those with moisture or salt exposure. Magnesium, being a more reactive metal, is especially prone to corrosion, often exhibiting significant deterioration when exposed to atmospheric conditions or in contact with water. Low alloy steels, while they may provide some resistance through alloying elements, still face challenges with uniform corrosion, especially in aggressive environments.

In contrast, gold and silver are noble metals that have excellent corrosion resistance, inherently preventing uniform surface corrosion under most conditions. Steel and aluminum can corrode but typically exhibit localized forms of corrosion like pitting, particularly in the case of aluminum. Copper and bronze also have good corrosion resistance due to the protective patina that forms on their surfaces, which helps to inhibit further corrosion. This makes magnesium and low alloy steels distinct in their pronounced vulnerability to uniform surface corrosion in various settings.