Conduction


In metals, the dominant method of conduction is through the movement of electrons. This method of conduction does not work in non-metals as there are no free electrons. When a metal is heated, the electrons closest to the heat source will vibrate more rapidly. Electrons then collide with these atoms and gain more kinetic energy. The electrons therefore move around faster and collide with other free electrons which then gain more kinetic energy. Kinetic energy is therefore transferred between the electrons and through the metal from the point closest to the heat source towards points futher away. The electrons all travel very short distances but are very fast moving therefore conduction of heat happens very quickly.

In metals and in insulators, there is conduction of heat due to the vibration of the atoms. As atoms closest to the heat source absorb heat/thermal energy, they make their neighbouring atoms vibrate more rapidly which then in turn make their neighbouring atoms vibrate more.
This is how conduction works... :)

Examples of conduction:

- wire gauzes used on tripods are metal therefore they are good heat conductors.
Gauzes on cookers are also metal so that heat is conducted quickly and food is cooked fast.

- Poor thermal conductors (insulators) are used for saucepan handles
so that they don't heat up and can still be handled.

- Metals are used for the containers which heat liquids e.g. pans, kettles on hobs

- Air is a poor conductor
so materials that trap air are used for insulation in lofts and hot water cylinders.