Thermal Expansion

What is Thermal Expansion?

Thermal expansion is the increase in the volume, and usually the length, of a substance when its temperature rises, caused by the particles gaining kinetic energy and moving over a greater range so that their average separation increases; gases expand most, liquids less and solids least for the same temperature rise.

This definition is part of the Thermal Physics chapter in Cambridge O Level Physics.

Concepts related to Thermal Expansion

• average separation
• Density
• expansion gap
• bimetallic strip
• liquid-in-glass thermometer
• Convection