Heat Transfer by Conduction

Steps:

• Hot solid's particles vibrate faster due to higher kinetic energy.
• When solids touch, vibrations pass from hot particles to adjacent cold particles at the interface.
• This transfers thermal energy through the cold solid, increasing its temperature.
• Process continues until thermal equilibrium is reached.

Why B is correct:

• Conduction is the transfer of thermal energy through direct particle collisions, as defined in the kinetic theory of matter.

Why the others are wrong:

• A: Expansion occurs due to heat but does not explain energy transfer mechanism.
• C: Heat rises applies to convection in fluids, not conduction in solids.
• D: Molecules in solids vibrate in fixed positions, not move freely like in gases or liquids.

Final answer: B