What is conduction?

• A. Transfer of heat energy through a material by bulk displacement of particles.
• B. Heat transfer through matter by convection.
• C. Conduction is the transfer of heat energy through a material by the motion of adjacent atoms and molecules without gross displacement of the particles.
• D. Radiation is energy transfer by electromagnetic waves.

Answer: (C)

Conduction is heat transfer through a substance by the direct interaction of neighboring particles, without the bulk movement of the material itself. In solids, energy moves as atoms vibrate and collide and as free electrons carry energy to nearby regions, so heat travels from hot to cold areas while the material stays essentially in place. This microscopic transfer is different from convection, where the fluid itself moves and carries heat, and from radiation, which uses electromagnetic waves to transfer energy through space or through transparent media. So this description—energy moving via the interactions of adjacent particles without overall displacement—best captures conduction.