what is freezing

Freezing is a physical process where a liquid turns into a solid when its temperature is lowered below its freezing point. It is a first-order thermodynamic phase transition, which means that as long as solid and liquid coexist, the temperature of the whole system remains very nearly equal to the melting point due to the slow removal of heat when in contact with each other. Freezing is a reversible change that does not involve any chemical changes. It is a change of state from liquid to solid, which occurs when the particles in a liquid lose energy, usually due to a drop in temperature. For most substances, the melting and freezing points are the same temperature; however, certain substances possess differing solid-liquid transition temperatures. Freezing is a common method of preserving food by lowering the temperature to inhibit microorganism growth.