Conduction is defined as what?

• A. The energy transferred by electromagnetic waves
• B. The direct transfer of heat from one substance to another that it is touching
• C. The transfer of heat by the movement of a fluid
• D. The energy stored in a system due to temperature

Answer: (B)

Conduction is the direct transfer of heat from a hotter object to a cooler one that are in contact. It happens because the particles in the hot region collide with neighboring particles, sharing energy and raising their temperatures step by step. In metals, freely moving electrons can also carry energy quickly from the hot part to the cooler part of the material, speeding up the process. A common example is a metal spoon getting warm when left in hot soup. This is different from radiation, which transfers heat through electromagnetic waves without contact, and from convection, where heat is carried by the bulk motion of a fluid. The idea in the other option describes thermal energy stored in a system, not the transfer of heat between objects.