AP BIOLOGY

Detailed explanation-1: -(2)Ice is less dense than liquid water, and when a solid crust of ice is on a lake, the water underneath is under pressure. The freezing point drops with increasing pressure for a substance, the liquid of which is denser than the solid. Click Here to return to the search form.

Detailed explanation-2: -Water is less dense as a solid than as a liquid. This property is important, as it keeps ponds, lakes, and oceans from freezing solid and allows life to continue to thrive under the icy surface.

Detailed explanation-3: -As water freezes it expands. So, ice has more volume (it takes up more space, but has less density) than water. Share with the children that this is a very special property of water.

Detailed explanation-4: -A frozen lake in winter with fish swimming below the surface is possible because of which property of water: cohesion.

Detailed explanation-5: -The extra hydrogen bonds that occur when water freezes increase the space between molecules, causing a decrease in overall density. In fact, each water ice molecule forms hydrogen bonds with four other molecules, while water molecules only form hydrogen bonds with an average of 3.4 other molecules.