Correct Answer:
B. Capillary action
Explanation:
The correct answer is Capillary action because the narrow microscopic spaces embedded within the paper fibers pull liquids upward against the force of gravity.
- Step 1 (Microscopic Matrix): Blotting paper is intentionally manufactured with a highly porous structure using loosely woven cellulose wood fibers. These interlaced pathways act like thousands of tiny, interconnected capillary tubes.
- Step 2 (Fluid Mechanics): When a liquid contacts the paper, the adhesive forces between the liquid molecules and the cellulose walls are stronger than the cohesive forces inside the fluid itself. This imbalance naturally draws the fluid rapidly up into the empty spaces.
- Incorrect Options:
- Viscosity is incorrect because viscosity measures a fluid's internal resistance to flow or thickness, which works to slow down absorption rather than aiding it.
- Surface tension is incorrect because surface tension is the cohesive force that holds a liquid's surface layer together, minimizing surface area, though it interacts with capillary pull.
- None of these is incorrect because capillary action is the exact physical mechanism responsible.