Which adhesive solidifies quickly under the influence of atmospheric moisture?

The adhesive that solidifies quickly under the influence of atmospheric moisture is cyanoacrylates. These adhesives are often referred to as "super glues" and are known for their ability to bond with a wide variety of materials almost instantaneously when they come into contact with moisture in the air. This quick curing process occurs because cyanoacrylate polymers react with the moisture to create a strong adhesive bond.

The rapid setting time makes cyanoacrylates particularly useful for applications requiring prompt adhesion, such as in hobby crafting, automotive repairs, and even in medical settings for small wound treatments. In the context of this question, the ability of cyanoacrylates to polymerize quickly in the presence of moisture distinguishes them from other adhesives listed.

Modified phenolics, anaerobics, and epoxies typically have different curing mechanisms that may depend on temperature, catalysts, or specific hardeners, which do not activate solely through moisture in the atmosphere. Therefore, the unique moisture-triggered curing property of cyanoacrylates is what makes them the correct choice here.