Why The electrical conductivity of copper decreases when temperature increases
The electrical conductivity of copper decreases as the temperature rises due to an increase in the number of lattice vibrations within the copper crystal lattice. Here's a more detailed explanation:
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Lattice Vibrations: In a solid material like copper, the atoms are arranged in a regular, repeating crystal lattice. At absolute zero temperature (0 Kelvin or -273.15°C), these atoms are completely stationary. However, as the temperature increases, the atoms start to vibrate around their equilibrium positions due to thermal energy. These vibrations are called lattice vibrations or phonons.
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Impact on Electron Movement: Copper is an excellent conductor of electricity because its outermost electrons are free to move throughout the lattice. These free electrons are responsible for carrying electric current. However, when the lattice vibrates at higher temperatures, it can scatter these free electrons.
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Increased Electron Scattering: The lattice vibrations create a "bumpy" path for the free electrons. As the electrons move through the lattice, they collide with the vibrating atoms, which scatter them in random directions. This scattering process hinders the flow of electrons and reduces the overall electrical conductivity of the material.