Capillary action is the phenomenon in which a liquid rises or falls in a narrow tube, such as a thin capillary, due to the intermolecular forces between the liquid and the walls of the tube. This process is driven by surface tension, which is the property of a liquid that allows it to resist external forces and minimize its surface area.

Explanation:

Surface tension is the force that holds the surface of a liquid together and gives it a tendency to minimize its surface area. It arises due to the cohesive forces between the molecules of the liquid. In the case of capillary action, surface tension plays a crucial role in the rise of the liquid in thin capillaries.

The rise of a liquid in a capillary tube can be explained by the balance of forces acting on the liquid. The adhesive forces between the liquid and the walls of the tube pull the liquid upward, while the cohesive forces within the liquid tend to hold it down. The surface tension of the liquid helps to overcome the cohesive forces and allows the liquid to rise in the capillary.

When the diameter of the capillary tube is small, the liquid experiences a greater adhesive force, as the surface area in contact with the walls of the tube is relatively larger. This leads to a larger capillary rise. On the other hand, when the diameter of the capillary tube is larger, the adhesive force is relatively smaller, resulting in a lower capillary rise.

Capillary action is not influenced by the mass or kinematic viscosity of the fluid. The temperature of the fluid may have some effect on the rate of capillary rise, but it is not the primary virtue responsible for the phenomenon.

In summary, the rise of a fluid in thin capillaries, known as capillary action, is primarily due to the surface tension of the fluid. Surface tension allows the liquid to overcome its cohesive forces and adhere to the walls of the capillary, resulting in the upward movement of the liquid.