1. Heat Transfers

2. Types of Heat Transfer Conduction Convection Radiation
Only happens in solids
Convection
Only happens in fluids (liquids & gases)
Radiation
Does not use particles
Pure heat energy
Can occur anywhere, even in a vacuum

3. Conduction (only occurs in solids)
Hot particles vibrate a lot
Cool particles vibrate a little

4. Conduction
Fast-moving particle (lots of energy) collide with neighbouring particles
This gives them more energy, making them vibrate faster

5. Conduction
This continues along the length of the solid until all the particles are vibrating with lots of energy

6. Convection (only occurs in fluids)
A fluid is a liquid or a gas
One part of the fluid gets heated – the particles move around with more energy
“Hot” particles are more spaced out so they are less dense, and rise
“Cool” particles or closer together so they are more dense, and fall

7. Radiation
When heat is moved from one place to another without using particles, it is called radiation
Heat radiation is infrared energy waves

8. Radiation
These energy waves can travel through any type of material but can be blocked by anything that is too thick or dense
Heat radiation can travel through a vacuum – this is how the heat from the Sun reaches us