Final answer:
Small insects can walk on water due to D)surface tension, where the cohesive forces among water molecules at the surface create a 'skin' strong enough to support their weight without breaking.
Step-by-step explanation:
Small insects are able to walk on the free surface of water due to surface tension. This surface tension arises from the cohesive forces between water molecules, which are especially significant at the surface where water meets air.
At this interface, the water molecules hold onto each other with such strength that they create a 'skin' at the surface, strong enough to support light objects.
Because of surface tension, it requires energy to break through the surface of water. Light insects, such as the water strider, do not possess enough force from gravity to break the surface.
Owing to their small mass and the way they distribute their weight over larger areas with their legs. The result is that these insects can walk on water as if they were walking on a trampoline, making small dents in the surface but not breaking through it.
Careful observations reveal that when these insects move, they are skating along the surface creating ripples, but maintaining their position above water.
This physical phenomenon is analogous to placing a needle or paper clip carefully on water: if done gently, these denser objects can be supported by surface tension as well, demonstrating the remarkable strength of water's surface under tension.