Final answer:
Water striders are able to walk on water due to surface tension, a property caused by the cohesive and adhesive properties of water molecules. This allows the insects to distribute their weight over a larger area and stay afloat.
Step-by-step explanation:
Water striders are able to walk on water due to a property called surface tension. Surface tension is the force that holds the molecules of a liquid together at its surface. In the case of water, the cohesive and adhesive properties of its molecules create a strong surface tension, allowing small insects like water striders to distribute their weight over a larger area and stay afloat. This property prevents the insects from breaking through the surface of the water and sinking.