【Daily Question】Theoretical Foundation 2020.10.10
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Multiple-choice question: The question is as shown in the figure ( ). Answer: C. Hint: Extra rewards will be given to those who can explain the solution process; the answer can be submitted there
The thermal conductivity of pure metals and most liquids decreases as temperature rises. The reason for this is that in metals, heat conduction occurs through collisions between electrons and metal ions, with the kinetic energy of the electrons being converted into internal energy of the metal. The higher the temperature, according to the molecular kinetic theory, the faster the electrons move, increasing the probability of collisions with metal ions; as a result, the electron gas cannot transfer its kinetic energy over long distances (which acts as a limitation), and thus the thermal conductivity decreases.
The essence of heat conduction lies in the energy loss that occurs during this process. As the temperature rises, the distance between molecules increases; it takes more energy for electrons to break free from the nucleus’s attraction and move to higher energy orbits. At the same time, as the temperature increases, the activity of metals increases, which raises the likelihood of diffuse reflection. As a result, the resistance/thermal conductivity decreases
This post was last edited by h20090630 on 2020-10-10 at 22:18. Explanation in C: Heat conduction essentially involves energy loss that occurs during this process. As the temperature rises, the distance between molecules increases; it takes more energy for electrons to break free from the nucleus’s attraction and move to higher energy levels. At the same time, as the temperature rises, the activity of metals increases, which raises the likelihood of diffuse reflection. As a result, the resistance/thermal conductivity decreases. Free electrons need to move in one direction, but during thermal motion they move in a chaotic manner! Similar to the superconducting phenomenon, superconductivity can be achieved at very low temperatures; however, the higher the temperature, the greater the thermal resistance