Final answer:
The property responsible for water "beading up" is surface tension, which is due to strong intermolecular forces, such as hydrogen bonding, that create a tightened film at the water's surface.
Step-by-step explanation:
The property responsible for the "beading up" of water is surface tension. This occurs because molecules within a liquid are pulled equally in all directions by intermolecular forces, with the exception of those at the surface. Molecules at the liquid's surface experience a net downward force since there are no liquid molecules above them to create an upward pull. This effect pulls the surface molecules into the liquid, resulting in a tightened film across the surface.
Liquids that have strong intermolecular forces, such as hydrogen bonding in water, exhibit high surface tension. This high surface tension enables water to form droplets on surfaces like a waxed car, as there is insufficient attraction between the polar water molecules and the nonpolar wax. This is also why objects denser than water can float on its surface, such as a paper clip, and insects can walk on water due to cohesive forces.