Page 13 - Curriculum Visions Dynamic Book

(Left and below) The open structure of ice makes it less dense than liquid water. Each water molecule has only four nearest neighbours with which it interacts by means of hydrogen bonds. The shape of the rings is mirrored in the sixfold symmetry of snowflakes.
The increased volume of ice compared with water is important in rock weathering, where the expanding ice on a wet surface levers loose blocks from the surface.
The forces involved as ice expands can easily crack a bottle. If plant cells with relatively fragile cell walls are frozen, they can rupture. This can damage crops both before they
are harvested and during
transit or storage.
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