Which process, powered by adhesion, causes water to move upward through a narrow tube such as the stem of a plant?

Which process, powered by adhesion, causes water to move upward through a narrow tube such as the stem of a plant?

• A. Capillary Action
• B. Adhesion
• C. Surface Tension
• D. Specific Heat Capacity

Answer: (A)

Capillary action describes how a liquid moves up a narrow tube because of adhesive forces between the liquid and the tube walls, with cohesion pulling the rest of the liquid along to form a continuous column. In plants, water climbs up the xylem as it adheres to the hydrophilic vessel walls, and cohesion among water molecules keeps the column intact as it rises. Surface tension plays a supporting role at the liquid–air interface, but the upward movement in a thin tube is driven mainly by the adhesive pull to the walls, transmitted through the cohesive water column. Specific heat capacity has no role in this movement.

Capillary action describes how a liquid moves up a narrow tube because of adhesive forces between the liquid and the tube walls, with cohesion pulling the rest of the liquid along to form a continuous column. In plants, water climbs up the xylem as it adheres to the hydrophilic vessel walls, and cohesion among water molecules keeps the column intact as it rises. Surface tension plays a supporting role at the liquid–air interface, but the upward movement in a thin tube is driven mainly by the adhesive pull to the walls, transmitted through the cohesive water column. Specific heat capacity has no role in this movement.