Describe the 6 changes of state that substances might undergo in terms of appearance and energy transfer.
When substances undergo changes of state, they can transition between different forms, accompanied by changes in appearance and energy transfer. The six changes of state are:
1. Melting: This occurs when a solid substance absorbs enough heat energy to transition into a liquid state. The appearance of the substance changes from solid to liquid, while the energy transfer involves the absorption of heat.
2. Freezing: The opposite of melting, freezing happens when a liquid substance loses enough heat energy to transform into a solid state. The appearance of the substance changes from liquid to solid, and the energy transfer involves the release of heat.
3. Evaporation: During evaporation, a liquid substance absorbs sufficient heat energy to transform into a gaseous state. The appearance of the substance changes from liquid to gas, and the energy transfer involves the absorption of heat.
4. Condensation: The reverse of evaporation, condensation occurs when a gaseous substance releases enough heat energy to transition into a liquid state. The appearance of the substance changes from gas to liquid, while the energy transfer involves the release of heat.
5. Sublimation: Sublimation happens when a solid substance transitions directly into a gaseous state without going through the liquid phase. The appearance of the substance changes from solid to gas, and the energy transfer involves the absorption of heat.
6. Deposition: The opposite of sublimation, deposition occurs when a gaseous substance releases enough heat energy to directly convert into a solid state without forming a liquid. The appearance of the substance changes from gas to solid, and the energy transfer involves the release of heat.
It is important to note that these changes of state are directly related to the exchange of heat energy. By adding or subtracting heat, substances can undergo these transformations, resulting in changes in appearance and energy transfer.