Thermal conductivity

Definition

Thermal conductivity is a material's ability to conduct heat. It measures the rate at which heat energy passes through a material.

5 Must Know Facts For Your Next Test

1. Thermal conductivity is denoted by the symbol $k$ and its SI unit is Watts per meter-Kelvin (W/m·K).
2. Materials with high thermal conductivity, such as metals, are good conductors of heat.
3. Insulators, like wood or rubber, have low thermal conductivity.
4. Fourier's Law of Heat Conduction describes how heat transfer through a material is proportional to the negative gradient in temperature and the area through which it flows.
5. $k$ values can vary significantly with temperature for some materials.

Review Questions

• What is the SI unit of thermal conductivity?
• How does Fourier's Law relate to thermal conductivity?
• Why do metals generally have higher thermal conductivity than insulators?

Related terms

Heat Transfer: The movement of heat from one place or material to another via conduction, convection, or radiation.

Conduction:

The process by which heat energy is transmitted through collisions between neighboring atoms or molecules.

Insulator:

A material that resists the flow of electric current and has low thermal conductivity.