Physics – 2.3.1 Conduction | e-Consult

When a metal bar is heated at one end, the particles within the heated region gain kinetic energy and vibrate more vigorously. These vibrating particles then collide with neighbouring particles, transferring some of their kinetic energy. This process continues as the vibrations are passed on through the metal lattice, causing the temperature to rise progressively along the bar. The heat energy essentially propagates through the metal as a wave of vibrating particles.

Metals are good conductors of heat due to their unique atomic structure and the presence of free electrons. Metals have a metallic bonding structure where valence electrons are delocalised and free to move throughout the entire metal lattice. These free electrons can readily absorb kinetic energy from the vibrating particles in the hotter region and transport it to cooler regions.

This mechanism of heat transfer, involving the movement of free electrons, is much more efficient than the vibration-based heat transfer in non-metals. The high mobility of electrons allows for rapid and effective heat propagation throughout the metal, making metals excellent conductors of heat. The more free electrons a metal has, the better its thermal conductivity will be.