AP BIOLOGY

Detailed explanation-1: -As the liquid cools down, the amount of potential energy is reduced and the molecules start to move slower. When the water temperature reaches around 0°C, the molecules stick together and form a solid – ice. Even in this solid stage, the molecules are still moving – we just can’t see it.

Detailed explanation-2: -Water is the only known non-metallic substance that expands when it freezes; its density decreases and it expands approximately 9% by volume.

Detailed explanation-3: -Water is unique, however, because its solid state (ice) is actually less dense than its liquid phase, allowing walleye and other aquatic life the ability to survive underneath the ice in cold, but unfrozen waters each winter.

Detailed explanation-4: -Ice is water in its frozen, solid form. Ice has different properties than most room-temperature liquids do in their solid form.