In which states of matter can conduction occur?

• A. Only gases
• B. In solids, liquids, and gases
• C. Only solids
• D. In vacuum

Answer: (B)

Conduction is the transfer of thermal energy through direct interactions between neighboring particles. In solids, energy moves by both lattice vibrations and, especially in metals, free electrons that quickly carry energy from hotter to cooler regions. In liquids and gases, energy is transferred by collisions and interactions between moving particles, so conduction still happens, though it’s often less efficient than in metals and can be aided or enhanced by fluid motion (convection). In vacuum there are no particles to collide or carry energy, so conduction cannot occur. So conduction can take place in solids, liquids, and gases.