Ice floats in water because, unlike most substances, the solid phase of water is less dense than its liquid phase. When water freezes, it expands slightly, and the resulting change in density is enough to allow ice cubes to float in a glass of water.Know More
Ice's expansion at its freezing point is due to the polar structure of water molecules. In the liquid phase, water molecules are always in motion and can be packed closely together. As the temperature drops, however, the molecules begin to form hexagonal crystals. The hydrogen bonds created in these crystals arrange the molecules in such a way that more space exists between them than in the liquid phase, resulting in an expansion of around 8.3 percent in volume. Since the water the ice displaces now weighs less than the ice itself, ice is buoyant and floats.
This unique property is important to the development of life on earth. Because ice floats, rivers and streams form a layer of ice during winter. If water behaved like most other solids and became denser when cooled, this ice would fall to the bottom of each body of water, freezing it solid and killing any living things under the surface.Learn more about Thermodynamics
The main reason oil floats in water is because it is less dense than water. Anything less dense than water will float, including the human body, which contains fat, a chemically similar substance to oil.Full Answer >
Corks float on water because it contains a lot of air making it less dense than water. Solids and liquids with less density float on denser liquids.Full Answer >
Styrofoam floats in water because it is less dense than water. This principle applies to all objects. That is, anything less dense than water will float, while anything more dense will sink.Full Answer >
Wood generally floats because it's less dense than the water it floats on. However, some woods are denser than water and will tend to sink.Full Answer >