freezing point

The temperature at which a liquid, releasing sufficient heat, becomes a solid. For a given substance, the freezing point of its liquid form is the same as the melting point of its solid form, and depends on such factors as the purity of the substance and the surrounding pressure. The freezing point of water at a pressure of one atmosphere is 0°C (32°F); that of liquid nitrogen is −209.89°C (−345.8°F).

See also state of matter