Conduction

Definition

Conduction is the transfer of heat through a material without any movement of the material itself. It occurs due to the collision and diffusion of particles within the substance.

5 Must Know Facts For Your Next Test

1. Conduction primarily takes place in solids, especially metals, because their atoms are closely packed and can easily transfer energy.
2. The rate of heat conduction is described by Fourier's Law: $q = -k \nabla T$, where $q$ is the heat flux, $k$ is the thermal conductivity, and $\nabla T$ is the temperature gradient.
3. Thermal conductivity ($k$) measures how well a material conducts heat; higher values indicate better conductors.
4. In non-metallic solids, conduction occurs mainly through lattice vibrations called phonons.
5. A temperature gradient must exist within the material for conduction to occur; heat flows from regions of higher temperature to regions of lower temperature.

Review Questions

• What type of materials are typically best at conducting heat? Why?
• State Fourier's Law and explain what each term represents in the context of heat conduction.
• Why does conduction require a temperature gradient within a material?

Related terms

Thermal Conductivity:

A measure of a material's ability to conduct heat, denoted by $k$. Higher values indicate better thermal conductivity.

Fourier's Law:

A law describing the rate of heat conduction through a material: $q = -k \nabla T$, where $q$ is the heat flux, $k$ is thermal conductivity, and $\nabla T$ is the temperature gradient.

Temperature Gradient:

The rate of change in temperature with respect to distance within a material. A necessary condition for conduction.