What characterizes uniform surface corrosion?

Uniform surface corrosion is characterized by a direct and overall chemical attack on a metal surface, leading to a gradual thinning of the material. This type of corrosion typically affects large areas of the metal evenly, often resulting in a general loss of material rather than localized damage.

In the context of the other options, spotty corroded areas would indicate pitting or localized corrosion, which is distinctly different from uniform surface corrosion. Corrosion at contact points suggests a crevice or galvanic corrosion scenario, where only specific areas experience damage due to differing environmental conditions or metal contact. Advanced decay at internal structures implies severe corrosion that has likely penetrated deeper into the material, which is not representative of the uniform surface corrosion that occurs more evenly across the surface area.

Overall, the key factor with uniform surface corrosion is its even distribution across the metal surface, distinguishing it from other types of localized or advanced corrosion.