A Level Physics Practice Exam

What occurs to the flow of electrons as temperature increases in metals?

1. The flow of electrons becomes smoother

2. The flow of electrons is hampered

3. The flow of electrons remains unchanged

4. The flow of electrons stops entirely

The correct answer is: The flow of electrons is hampered

As temperature increases in metals, the flow of electrons is hampered due to increased lattice vibrations within the metal's crystalline structure. At higher temperatures, the atoms in the metal vibrate more vigorously, which causes more collisions between the moving electrons and the atoms. These collisions impede the flow of electrons, making it more difficult for them to conduct electricity. This phenomenon can be understood in the context of electrical resistance, which generally increases with temperature for conductive materials like metals. Thus, while electrons are still able to move and flow in the metal, their movement becomes less efficient, leading to a decrease in electrical conductivity as temperature rises. This is consistent with the observed behavior in conductive materials where increased temperature correlates with increased resistance.