Which statement best describes conduction as a mode of heat transfer?

Which statement best describes conduction as a mode of heat transfer?

• A. It transfers heat through direct contact between substances.
• B. It transfers heat through empty space.
• C. It requires a fluid to move.
• D. It involves radiation.

Answer: (A)

Conduction is heat transfer through direct contact between substances. When one region is hotter, its particles have more energy and collide with neighboring particles, passing some of that energy along at the contact surface or through the material. In solids, energy moves via interactions in the lattice, and in metals, free electrons carry energy quickly from the hot side to the cooler side. This transfer happens without bulk movement of the substance itself, relying on particle interactions at interfaces and within the material. Transferring heat through empty space describes radiation, which does not require contact. Requiring a moving fluid describes convection, where a fluid carries heat as it circulates. The statement involving radiation does not describe conduction accurately.

Conduction is heat transfer through direct contact between substances. When one region is hotter, its particles have more energy and collide with neighboring particles, passing some of that energy along at the contact surface or through the material. In solids, energy moves via interactions in the lattice, and in metals, free electrons carry energy quickly from the hot side to the cooler side. This transfer happens without bulk movement of the substance itself, relying on particle interactions at interfaces and within the material.

Transferring heat through empty space describes radiation, which does not require contact. Requiring a moving fluid describes convection, where a fluid carries heat as it circulates. The statement involving radiation does not describe conduction accurately.