Condensation and Freezing Release Heat

- Condensation is the process by which a gas or vapor changes into a liquid state. When water vapor condenses, it releases heat energy to the surroundings. This occurs because the molecules in the gas phase have higher kinetic energy compared to the liquid phase. As they lose energy and slow down, they release heat. For example, when water vapor condenses on a cold surface to form dew, heat is released.

- Freezing is the process by which a liquid changes into a solid state. When a substance freezes, it releases heat energy. This is because the molecules in the liquid phase lose energy and slow down, releasing heat as they arrange themselves into a more ordered solid structure. For example, when water freezes into ice, heat is released.

Vaporization and Melting Absorb Heat

- Vaporization is the process by which a liquid changes into a gas or vapor. When a substance vaporizes, it absorbs heat energy from the surroundings. This occurs because the molecules in the liquid phase gain energy and speed up to overcome intermolecular forces and transition into the gas phase. For example, when water boils and turns into steam, heat is absorbed from the surroundings.

- Melting is the process by which a solid changes into a liquid state. When a substance melts, it absorbs heat energy. This is because the molecules in the solid phase gain energy and vibrate more rapidly, breaking the intermolecular forces holding them together and transitioning into the liquid phase. For example, when ice melts into water, heat is absorbed from the surroundings.

Conclusion

- The processes of condensation and freezing release heat, while vaporization and melting absorb heat.

Condensation and freezing release heat that lead to a decrease in kinetic energy of molecules. When the substance gets cool enough its particles become slower or stop their movement and change their phase into liquid and solid on condensing and freezing respectively.