Final answer:
The property of water that allows it to be filled above the rim of a glass without spilling is cohesion, which creates surface tension, enabling the water to form a dome-like shape and hold denser objects on its surface.
Step-by-step explanation:
The property of water that allows someone to fill a glass slightly above the rim without the water flowing over is known as cohesion. Cohesion refers to the attraction between water molecules, which is primarily due to hydrogen bonding. Because of cohesive forces, water can form a dome-like shape above the rim of a glass without spilling. This is further described as surface tension, a phenomenon that allows water to resist external force, acting like a thin skin at the water-air interface. Furthermore, cohesive and adhesive properties enable various objects denser than water, like a sewing needle or a paper clip, to 'float' on the water's surface if placed gently without breaking the surface tension.
The property of water that allows someone to fill a glass slightly above the rim without the water flowing over is surface tension. Surface tension is the result of the cohesive forces between water molecules at the surface of the liquid.
Water molecules are attracted to each other due to hydrogen bonding. This cohesive force creates a "skin" or film at the surface of the water, forming a sort of elastic membrane. When you pour water into a glass slightly above the rim, the surface tension prevents the water from easily overflowing by holding it in a slightly rounded shape above the rim. This effect allows you to exceed the rim's height without an immediate spill, although if you continue to add more water, it will eventually overflow.