# Revise GCSE Physics

Question:What is conduction?

Everything is made of particles. The particles can be atoms or molecules.

In any solid material all the particles are bound into a fixed position with respect to all the other particles, by bonds between the particles, which is why a solid has a fixed shape.

The individual particles are free to vibrate about their fixed positions. These vibrations increase as the material becomes hotter. Bigger vibrations meams more kinetic energy.

Conduction occurs when particles pass on their vibrational kinetic energy by collisions with their neighbouring particles.

Conduction from one end of an object to the other is caused by a series of such collisions.

The below diagrams show examples of this.

1 Heat is transferred to the corner particle from outside the solid. The size and speed of this particles vibration increases. This is called an increase in Kinetic Energy (or an increase vibrational energy). This means that particles temperature has increased.

2. The corner particle collides with its neighbouring particles and passes on some of its kinetic/vibrational energy to them. These particles now have more kinetic/vibrational energy and their vibrations are also larger and faster.

3 Further collisions spread the extra vibrational energy further. The spread of heat by conduction occurs by a series of such collision until the Heat energy being transferred at one end has spread along the length of the material.