- Conduction happens mainly in solids
- All atoms vibrate, but vibrate more when heated
- Heat spreads by conduction when atoms increase their vibrations, and pass this energy on to those nearby.
- In metals free electrons carry the heat energy faster than the atomic vibrations and transfer it by colliding with other electrons and atoms.
- Don’t say ‘heat rises’ say ‘hot air rises’ or ‘hot water rises’.
- Gases and liquids tend to change density with changes in temperature.
E.G. If heated air decreases in density. The surrounding air is cooler and denser. This makes it heavier, so it falls beneath the hot air forcing it upwards.
- Radiators give off convection currents.