Thermal Conduction (CIE IGCSE Physics: Co-ordinated Sciences (Double Award))

Extended tier only

• Conduction is the transfer of heat from one region to another through particle vibrations and the movement of free electrons
• Conduction is the main method of thermal energy transfer in solids

• Metals are the best thermal conductors
  • This is because they have a high number of free electrons

Conduction: the atoms in a solid vibrate and collide, transferring energy

• Conduction can occur through two mechanisms:
  • Atomic vibrations
  • Free electron collisions

• When a substance is heated, the atoms, or ions, start to move around (vibrate) more
  • The atoms at the hotter end of the solid will vibrate more than the atoms at the cooler end
  • As they do so they bump into each other, transferring energy from atom to atom
  • These collisions transfer internal energy until thermal equilibrium is achieved throughout the substance
  • This occurs in all solids, metals and non-metals alike

• Additionally, if a solid contains free electrons, these can travel through the material freely and transfer thermal energy through collisions