A water strider stands and skates on a pond surface without sinking, though a dropped pebble of similar weight plunges through. Which property of water best explains the difference?

Core Concept

At an air-water interface, surface molecules experience unequal attraction because no water molecules lie above them. Cohesive hydrogen bonding among these surface molecules produces surface tension, behaving like a stretched elastic sheet. A water strider spreads its weight across legs covered with hydrophobic microsetae, dimpling the film without piercing it, whereas a concentrated impact exceeds the film strength and breaks through. The property emerges purely from intermolecular attraction, showing how water's molecular structure generates emergent behavior.