The process when water freezes is called solidification or freezing. This occurs when the temperature of water drops below 0 degrees Celsius (32 degrees Fahrenheit), causing the liquid molecules to lose energy and arrange themselves into a solid crystalline structure known as ice. Freezing is a physical change, meaning the chemical composition of the water remains unchanged. Factors such as pressure can influence the freezing point, but under standard atmospheric conditions, water uniformly transitions to ice, which is less dense and allows it to float.