EVERYDAY SCIENCE

Detailed explanation-1: -There is no temperature change until a phase change is completed. The temperature of a cup of soda and ice that is initially at 0 °C °C stays at 0 °C °C until all of the ice has melted. In the reverse of these processes-freezing and condensation-energy is released from the latent heat (see Figure 11.9).

Detailed explanation-2: -Heat going into a substance changes it from a solid to a liquid or a liquid to a gas. Removing heat from a substance changes a gas to a liquid or a liquid to a solid.

Detailed explanation-3: -Thus any transition from a more ordered to a less ordered state (solid to liquid, liquid to gas, or solid to gas) requires an input of energy; it is endothermic. Conversely, any transition from a less ordered to a more ordered state (liquid to solid, gas to liquid, or gas to solid) releases energy; it is exothermic.

Detailed explanation-4: -Condensation happens when molecules in a gas cool down. As the molecules lose heat, they lose energy and slow down.

Detailed explanation-5: -Condensing:The transition from the gas phase to the liquid phase. Sublimination: The transition from the solid phase to the gas phase.