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Posted by on Jan 14, 2016 in Tell Me Why |

Why Does an Ice Cube Float?

Why Does an Ice Cube Float?

Ice cube floats because it is lighter than water. When water freezes, it increases its volume (expands) by about one-tenth. When 10 quarts of water freeze, then, 11 quarts of ice form. Thus, ice is lighter than water and will float.

This expansion of ice also explains why one-tenth of a floating ice cube is above the surface. Ice decreases about one-tenth in size as it melts.

Therefore, the water from a melted ice cube will take up only as much space in the glass as the cube took up when it was floating. So the water level in a glass doesn’t rise as the ice melts.

The fact that ice cubes float on water tells us something important about water. When water freezes and changes into a solid, its molecules arrange themselves so that they occupy more space.

Content for this question contributed by Patrick Lorish, resident of North Tonawanda, Niagara County, New York, USA