Thermal Expansion
- When materials are heated, they expand
- This expansion happens because the molecules start to move around (or vibrate) faster, which causes them to knock into each other and push each other apart
When a solid is heated, the molecules vibrate more, pushing each other apart
Note: When this happens, it is the space taken up by the molecules that increases. The molecules themselves remain the same size.
- Thermal expansion occurs in solids, liquids and gases
- When temperature is increased (at constant pressure);
- Solids will tend to expand the least
- Gases expand the most
- Liquids fall in between the two