1. 25/08/2019
Heating and Cooling
W Richards
The Weald School

2. Heat and Temperature
25/08/2019
Heat is a type of energy that will flow from a warm area to a colder one. For example…
This cup of coffee will ____ ____ because it is _____ ____ heat energy into the surroundings.
This drink (taken out of the fridge) will _____ ___ because it is _____ ___ heat energy from the surroundings.
Words – giving out, warm up, taking in, cool down

3. Particle theory revision
25/08/2019
Particle theory is all about explaining the properties of solids, liquids and gases by looking at what the particles do.
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SOLIDS
In a solid the particles ______ around a _____ position. There is a ______ force of attraction between each particle and they are very _____ together
Words – strong, close, vibrate, fixed

4. Words – fixed, collide, quickly, close, very, solids
25/08/2019
LIQUIDS
GASES
In a liquid the particles are _____ together but can move in any direction. They won’t keep a _____ shape like _____ do.
In a gas the particles are very far apart and move _____ in all directions. They often ______ with each other and because they are far apart they can be easily _______.
Words – fixed, collide, quickly, close, very, solids

5. Heating a solid
25/08/2019
When a solid is heated it expands. We can use particle theory to explain why:
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When a solid, liquid or gas heats up it will expand.
When a solid, liquid or gas cools down it will contract.

6. Changes of state
25/08/2019
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7. Changes of State
25/08/2019
What are these processes called? Choose from freezing, evaporating, melting, condensing

8. Heating ice
25/08/2019
Temp/OC
150
100 50
-50
This flat line shows where energy is being used to push the particles further apart for evaporation
This flat line shows where energy is being used to break bonds – this has to be done during melting
Time/s

9. Conduction
25/08/2019
CONDUCTION is when heat moves through a ________. Metals are better conductors of heat than plastic or wood. This is why…
These parts are made of plastic or wood:
These parts are made of metal:

10. Conduction
25/08/2019
In this experiment we saw that liquid water is a poor conductor of heat. The ice cube did not melt even though the water above it was boiling.
Air is also a poor conductor of heat. This is how many types of house insulation and clothing keep us warm.

11. Words – sun, absorbs, nothing, warmer, waves
Radiation
25/08/2019
When you wear a black t-shirt on a hot, sunny day you would feel ______ than if you wore white. This is because black ________ infrared radiation (i.e. heat) from the sun better than white does.
I’m cool!
I’m very hot!
Conduction is when heat travels through a solid and convection happens in a liquid or gas, but radiation can happen through absolutely ________ because the heat is moving by ______. This is how heat reaches us from the ____.
Words – sun, absorbs, nothing, warmer, waves

12. Words to use: expands, radiators, dense, heated, current, float
Convection
25/08/2019
Convection is all about when a gas or liquid (“fluid”) moves and carries heat with it. When the fluid is heated it ____________. This means that it will become less __________ than the colder fluid around it. Because of this the warmer fluid will try to “_______” over the colder fluid, and this is why warm air rises. This is called a convection ___________. This is how heat reaches us from the ___________ in this room.
Words to use: expands, radiators, dense, heated, current, float