Question

Why does ice float on water?

Answer 1

Density:

1. The mass per unit volume of a substance is known as density.
2. Mathematically, it can be expressed as $d=\frac{\mathrm{m}}{V}$, where $d$ is the density, $m$ is the mass of the body, and $V$ is the volume
3. Density is inversely proportional to volume. Thus, as the volume of a substance increases, its density decreases.

Explanation:

1. It is understood that the density of an object determines whether it will float or sink. If the density of one object is lesser than the other in the mixture then it will float. Whenever an object float, it displaces the amount of liquid equal to its weight.
2. The density of ice is $0.917\mathrm{g}‐{\mathrm{cm}}^{-3}$ and the density of water is $1\mathrm{g}‐{\mathrm{cm}}^{-3}$. The density of ice is less than water because of hydrogen bonding and its structure is similar to a cage.
3. When water freezes, the molecules establish more stable hydrogen bonds, which locks them firmly in place. The molecules cannot create as many hydrogen bonds as normal water molecules because they are not free to move.
4. As a result, frozen water molecules are not as close together as liquid water molecules, leading to a lower density.
5. Thus, when water freezes into ice, hydrogen bonds develop, allowing the molecules to be spread further apart, taking up more space, lowering the total density, and allowing it to float in the water.