What happens to temperature during a material's change of state?

During a material's change of state, such as melting or boiling, the temperature remains constant despite the absorption of energy. This phenomenon occurs because the energy added to the substance during these phase transitions is used to change the arrangement of the particles rather than to increase their kinetic energy, which is what temperature measures.

For instance, as ice melts into water, the added energy breaks the bonds between the ice molecules, allowing them to move more freely. During this process, although energy is being absorbed (known as latent heat), the temperature of the ice-water mixture stays at 0°C until all the ice has melted. Only once the substance has completely changed state does the temperature begin to rise again.

This principle is vital in various applications, such as understanding how climate affects weather patterns and how refrigerators work, as it explains why certain temperatures are maintained during freezing and boiling processes.