What does the size of the opening between solids affect in capillary attraction?

The size of the opening between solids significantly impacts the distance that a liquid can be drawn into that opening due to capillary attraction. Capillary action occurs when liquid rises or falls in a narrow space due to the effects of cohesion (the attraction between liquid molecules) and adhesion (the attraction between liquid molecules and the solid surfaces).

In narrower openings, the surface tension of the liquid is stronger relative to gravitational forces, allowing the liquid to be pulled further up into the space. This means that smaller openings can result in a greater capillary rise, as the adhesive forces between the liquid and the solid walls can overpower the pull of gravity over a greater height.

Understanding this principle allows for better control in various applications involving fluids, such as in welding or brazing processes, where proper flow of filler material into joints is crucial for creating solid and reliable bonds. The other options relate to different properties of fluid dynamics but do not directly address the specific relationship between the opening size and the distance liquid can be drawn by capillary action.