When you put water in a bottle and place it in the freezer, several things happen. Initially, the water starts to cool down. As the temperature drops below its freezing point (0 degrees Celsius or 32 degrees Fahrenheit), the water undergoes a phase change from liquid to solid, forming ice.
During this process, the water molecules arrange themselves into a crystalline structure as they slow down and bond together. The expansion of water as it freezes causes it to occupy a larger volume than it did in its liquid state. This expansion can lead to the bottle cracking or bursting if it is not designed to withstand the pressure.
If the bottle is made of a sturdy material that can handle the expansion, such as a plastic or glass bottle specifically designed for freezing, it will contain the expanding ice. However, it is important to leave some headspace in the bottle to accommodate the expansion and prevent it from breaking.
Once the water has completely frozen, it will remain in a solid state until the temperature rises above its melting point. At that point, the ice will begin to melt and revert to a liquid form again.
It's worth noting that freezing water in a closed bottle can be potentially dangerous due to the risk of the bottle bursting. It is generally recommended to use containers designed for freezing and to leave some room for expansion or to use open containers that allow the water to expand without causing any damage.