What property of water allows water molecules to stick to each other, resulting in droplets and surface tension?

Water's ability to stick to itself, forming droplets and creating surface tension, is known as cohesion. Cohesion occurs due to hydrogen bonding between water molecules, where the positive end of one molecule is attracted to the negative end of another. This strong intermolecular force causes water to resist separation, leading to phenomena like the formation of droplets on a surface and the ability to support small objects on its surface, illustrating surface tension.

While adhesion refers to the attraction between water molecules and other substances, it is not the process that explains the binding between water molecules themselves. Viscosity describes a fluid's resistance to flow, which, while related to the movement of water, does not specifically address the sticking of water molecules to one another. Capillary action involves the upward movement of water against gravity, usually through narrow spaces, driven by both cohesion and adhesion, but does not refer directly to the sticking of water molecules to themselves. Therefore, cohesion is the term that best captures the property of water that allows for the formation of droplets and surface tension.