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20/03/16 Heating and Cooling

20/03/16 Heat and Temperature 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. Heat is a type of energy that will flow from a warm area to a colder one. For example… Words – giving out, warm up, taking in, cool down

20/03/16 Particle theory revision Particle theory is all about explaining the properties of solids, liquids and gases by looking at what the particles do. In a solid the particles ______ around a _____ position. There is a ______ force of attraction between each particle and they are very _____ together SOLIDS Words – strong, close, vibrate, fixed View animation

20/03/16 LIQUIDS GASESIn 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

20/03/16 Heating a solid When a solid is heated it expands. We can use particle theory to explain why: View animation When a solid, liquid or gas heats up it will expand. When a solid, liquid or gas cools down it will contract.

20/03/16 Changes of state View animation

20/03/16 Changes of State What are these processes called? Choose from freezing, evaporating, melting, condensing

20/03/16 Heating ice 150 100 50 0 -50 Temp/ O C Time/s This flat line shows where energy is being used to break bonds – this has to be done during melting. This flat line shows where energy is being used to push the particles further apart for evaporation

20/03/16 Conduction 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:

20/03/16 Conduction 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.

20/03/16 Radiation 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. 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 ____. I’m very hot!I’m cool! Words – sun, absorbs, nothing, warmer, waves

20/03/16 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