Jäädytyksen

Jäädytys, commonly known as freezing, is a fundamental physical process where a liquid transforms into a solid due to a decrease in temperature. This phase transition occurs when the thermal energy of the liquid's molecules is reduced to a point where intermolecular forces overcome their kinetic energy, causing them to arrange into a more ordered, crystalline structure. The temperature at which this transformation happens is called the freezing point. For pure substances, the freezing point is a characteristic constant, like the melting point which is the same temperature but in reverse. For water, this point is 0 degrees Celsius or 32 degrees Fahrenheit at standard atmospheric pressure. Impurities in a liquid can lower its freezing point, a phenomenon known as freezing point depression, which is utilized in applications like de-icing roads. Freezing is a reversible process; when heat is added to a solid, it will melt back into a liquid at its melting point. The process of freezing involves the removal of latent heat of fusion, the energy that must be extracted from the substance at its freezing point to allow it to change from liquid to solid. This principle is applied in various fields, including food preservation, where freezing slows down the enzymatic and microbial activity that causes spoilage, and in scientific research for cryopreservation of biological samples.