Ice is a solid form of water that typically forms in cold environments. It can also form in hot environments, but only if the temperature is below freezing point. Ice appears white and opaque, but it is actually clear. The ice crystals that make up ice are very small and have a hexagonal shape.
The structure of ice is similar to that of other solids, such as rocks. Ice has a crystalline structure, meaning that the molecules are arranged in a regular pattern. The molecules are held together by strong bonds called hydrogen bonds. Hydrogen bonds are much weaker than the covalent bonds that hold together the atoms within molecules, but they are stronger than van der Waals forces, which allow molecules to stick together temporarily.
Ice is less dense than liquid water, so it floats on water. This property is due to the fact that the hydrogen bonds between water molecules are broken when water freezes, causing the molecules to take up more space. This expansion of volume causes ice to be less dense than liquid water.
The melting point of ice (0 degrees Celsius) is lower than its boiling point (100 degrees Celsius). This means that ice can exist in both its solid and liquid states at Earth’s surface under normal conditions (i.e., not too close to a heat source). When heated, ice first melts and then vaporizes into steam or water vapor just like any other substance with a lower melting point than its boiling point (such as mercury).