Answer :
The cohesion of water molecules, their adhesion to the walls of narrow tubes, and the resulting rise of water in the tubes is called capillary action.
Capillary action, also known as capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. This occurs due to the intermolecular forces between the liquid and the surrounding solid surfaces, such as the walls of a narrow tube. In the case of water, this is primarily due to the cohesive forces between water molecules, which are attracted to each other, and the adhesive forces between water molecules and the tube walls, which are attracted to each other more than the water molecules are attracted to themselves.
When water is placed in a narrow tube, the adhesion of water to the tube walls causes the water to climb the walls, and the cohesion between water molecules helps to pull more water up the tube. This results in a concave meniscus and a rise in the water level within the tube, which is higher than the surrounding water level. The height to which the water rises is inversely proportional to the diameter of the tube; the narrower the tube, the higher the water will rise.
