A student claims that since the three phases have different amounts of energy, molecules in substances gain or lose energy only during phase transitions. Explain what is wrong with this student's reasoning.

Question

ujjwal · Answer

The amount of energy possessed by a substance in a certain phase in not same at all temperatures..
The amount of energy (of molecules) is greater at higher temperature than at lower temperature even when it is in the same phase.. So, energy can be gained and lost just by increasing and decreasing the temperature in the same phase..

Its true that molecules in substances gain or lose energy during phase transitions. So, the student is correct but he is "partially correct".. He missed the above reasoning..

anonymous · Answer

Wow, thanks! That was very helpful.