What property of water allows insects like water striders to walk on its surface?

The ability of insects like water striders to walk on the surface of water is primarily due to surface tension. This phenomenon arises from the cohesive forces between water molecules, which are largely due to hydrogen bonding. While hydrogen bonding is fundamental to the structure and properties of water, it is the resulting surface tension that provides the necessary force to support the weight of lighter objects, such as water striders.

Surface tension is the elastic-like force existing at the surface of a body of liquid, where the water molecules at the surface are pulled inward by cohesive forces, creating a "skin" effect. This allows small insects to distribute their weight over a larger area, preventing them from breaking through the surface tension and sinking.

This helps clarify why surface tension is the relevant property in this context. Hydrogen bonding contributes to the overall cohesive forces, but it is specifically surface tension that enables water striders to walk on water without sinking.