A water strider rests on the surface of a pond without sinking, and the surface dimples under each of its feet instead of breaking. Which property of water supports the insect?

In a maple, water inside a xylem vessel clings to the vessel's cellulose walls, and the film of water creeping up those walls helps draw the column upward. Which property is at work between the water and the wall?

Early on a cool morning, dew on a spider's web does not spread along the silk as a thin sheet. It gathers into round beads spaced along the strand. Which property of water accounts for the beading?

A dog on a hot day pants rapidly, and water evaporates from the wet surfaces of its tongue and airways. Its body temperature falls even though it is not in the shade. Which property of water explains the cooling?

A rocky tide pool sits in full sun for four hours. The dark rock beside it becomes too hot to touch, while the water in the pool warms by only about 3 degrees Celsius. Which property of water explains the difference?

In January a pond is capped with a sheet of ice, and painted turtles and pond snails overwinter in liquid water below it. Which property of water makes that refuge possible?

Blood plasma carries glucose, amino acids, sodium ions and urea from one organ to another, all of them dispersed evenly in the fluid rather than settling out. Which property of water makes plasma able to carry this cargo?

Water climbs the narrow dead cells of a fern's stem against gravity: it clings to the cell walls and, as it rises, drags the molecules behind it upward too. Which combination is responsible?

Most substances contract and grow denser when they solidify, but water expands. What happens to the water molecules as they freeze that produces this result?

Heating 1 gram of water by 1 degree Celsius takes far more energy than heating 1 gram of iron by the same amount. At the molecular level, where does that extra energy go?

Table salt stirred into water disappears into solution, but olive oil poured into the same beaker separates into a layer. What accounts for the difference?

Water has a mass per molecule close to that of methane, yet water is a liquid at room temperature while methane is a gas. What explains this?

Suppose water were a nonpolar molecule with no partial charges, everything else unchanged. What would this mean for the cytoplasm of a cell?

Imagine water molecules formed no hydrogen bonds, so water had a specific heat as low as that of dry sand. How would a small mammal be affected on a day when the air warms quickly?

In a tall tree, water is pulled up the xylem as a continuous column under tension. If the attraction between neighboring water molecules were greatly weakened, what would happen first?

Suppose evaporating water carried away very little heat. A marathon runner still sweats normally in dry air. What is the most likely consequence?

Almost every reaction inside a cell takes place in the watery cytoplasm rather than in a dry compartment. Which statement best explains why?

A plant in dry soil cannot take up the nitrate and potassium beside its root hairs, but it takes them up quickly once the soil is watered. A student says the water just keeps the roots moist. What does the water actually do?

A resting adult releases heat continuously from cellular respiration, yet core body temperature stays near 37 degrees Celsius through the day. How does the body's water contribute to that stability?

Two runners work equally hard at 35 degrees Celsius. One runs in dry desert air and stays cool; the other runs in humid tropical air, stays drenched in sweat and overheats. Why does the same amount of sweat cool one runner and not the other?