In conduction, how is heat transferred between substances?

In conduction, how is heat transferred between substances?

• A. Molecule to molecule
• B. Through waves in a vacuum
• C. By bulk motion of a fluid
• D. By chemical reaction

Answer: (A)

Conduction transfers heat through direct contact where energy moves from hotter particles to cooler ones by collisions and vibrations at the boundary and within the material. When one object is hotter, its particles have more kinetic energy and share some of that energy with neighboring particles, gradually raising the temperature of the cooler object. In metals, free electrons also carry energy rapidly and transfer it to other regions or materials through collisions, speeding the process. This mechanism requires contact and can occur in solids, liquids, or gases, but not in a vacuum where there are no particles to exchange energy. Radiation would handle heat transfer in a vacuum, not conduction, and convection involves bulk fluid motion rather than direct particle-to-particle contact. So heat is conducted by molecule-to-molecule energy transfer through direct contact.

Conduction transfers heat through direct contact where energy moves from hotter particles to cooler ones by collisions and vibrations at the boundary and within the material. When one object is hotter, its particles have more kinetic energy and share some of that energy with neighboring particles, gradually raising the temperature of the cooler object. In metals, free electrons also carry energy rapidly and transfer it to other regions or materials through collisions, speeding the process. This mechanism requires contact and can occur in solids, liquids, or gases, but not in a vacuum where there are no particles to exchange energy. Radiation would handle heat transfer in a vacuum, not conduction, and convection involves bulk fluid motion rather than direct particle-to-particle contact. So heat is conducted by molecule-to-molecule energy transfer through direct contact.