If the adhesive forces are greater than the cohesive forces, what happens to a liquid on a surface?

• A. The liquid will wet the surface.
• B. The liquid will bead up.
• C. The liquid will evaporate.
• D. The surface will dissolve the liquid.

Answer: (B)

When a liquid is more attracted to the surface (adhesion) than to itself (cohesion), it spreads out over the surface and wets it. This results in a low contact angle and the liquid forming a thin film or flattened drop rather than a tight bead. In other words, the liquid will wet the surface.

If cohesion were stronger than adhesion, the liquid would bead up, forming a higher contact angle and not spreading as much. Evaporation and dissolution are separate processes and don’t describe the spreading behavior.