Which term describes the movement of water upward through narrow tubes due to cohesion and adhesion?

Which term describes the movement of water upward through narrow tubes due to cohesion and adhesion?

• A. Capillary action
• B. Evaporation
• C. Condensation
• D. Precipitation

Answer: (A)

The movement of water upward through narrow tubes due to cohesion and adhesion is known as capillary action. This happens because water molecules like to stick to each other (cohesion) and to the surfaces of the tube (adhesion). In a thin tube, the adhesive forces pull the water up along the walls, while the cohesive forces keep the water column intact, allowing it to rise against gravity. The effect is stronger in smaller-diameter tubes, where capillary rise is more pronounced, and you can see it in how plants draw water up from their roots through the tiny vessels in their stems, or how a paper towel draws up a spill. Evaporation, condensation, and precipitation involve phase changes or atmospheric processes and don’t describe water moving upward inside narrow tubes, so they’re not the right terms here.

The movement of water upward through narrow tubes due to cohesion and adhesion is known as capillary action. This happens because water molecules like to stick to each other (cohesion) and to the surfaces of the tube (adhesion). In a thin tube, the adhesive forces pull the water up along the walls, while the cohesive forces keep the water column intact, allowing it to rise against gravity. The effect is stronger in smaller-diameter tubes, where capillary rise is more pronounced, and you can see it in how plants draw water up from their roots through the tiny vessels in their stems, or how a paper towel draws up a spill. Evaporation, condensation, and precipitation involve phase changes or atmospheric processes and don’t describe water moving upward inside narrow tubes, so they’re not the right terms here.