Conduction in Metals Involves Phonons and Electrons

Steps:

• Walls consist of wood (insulator) and steel (metal conductor).
• Thermal conduction in solids occurs via particle vibrations in all materials.
• Metals like steel additionally transfer heat through free electron movement.
• The accurate description matches steel's dual mechanism.

Why B is correct:

• In metals, Fourier's law of heat conduction incorporates both lattice vibrations (phonons) and electron diffusion, explaining high thermal conductivity.

Why the others are wrong:

• A: Wood conduction relies on vibrations, not molecular movement through the solid lattice.
• C: Solids like wood do not involve bulk molecular movement; only vibrations occur.
• D: Metal conduction includes particle vibrations alongside electron movement, not electrons alone.

Final answer: B