Heating and Cooling

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 to use – giving out, warm up, taking in, cool down

Heat energy How much heat energy an object has depends on its temperature AND how much of it there is… The sparkler is at a higher temperature than the bath, but the bath is MUCH heavier, so it has more heat energy.

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 to use – strong, close, vibrate, fixed

LIQUIDS GASES In a liquid the particles are _____ together but can move in ____ direction. They won’t keep a _____ shape like _____ do. In a gas the particles are ____ 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, any, quickly, close, very, solids

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

Heating ice 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

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:

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.

Radiation When you wear a black t-shirt on a hot, sunny day you would feel warmer than if you wore white. This is because black absorbs 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 nothing because the heat is moving by waves. This is how heat reaches us from the sun. I’m very hot! I’m cool!

Convection 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

Evaporation Heat can also be lost when water evaporates (this is how we cool off when we sweat): This water will evaporate because the water molecules have enough energy to “escape” from the rest of the water. When they do so they will take heat with them.