Lesson Starter Draw a picture and write a description of the particles in: a) A solid b) A liquid c) A gas

What’s the matter? So far..

To investigate change of state Learning Intention To investigate change of state

Liquids turn into solids? What word describes.. Solids turn into liquids? Liquids turn into solids?

Apparatus Goggles Bunsen Burner Tripod Beaker Test tube Dropper Cotton wool Nail varnish remover Beaker of crushed ice

Method Light your Bunsen burner and leave it on the safety flame Measure 100 mls of water into your beaker Place beaker on tripod stand and heat using the flame from the Bunsen until it boils then TURN THE BUNSEN OFF Put 5 drops of nail varnish remover into the test tube Bung the top of the test tube loosely Sit the test tube in the warm water and watch what happens Take the test tube out of the water and run it under the cold tap- what happens?

What did you see? What did you see when you heated the nail varnish remover? What does this tell you about heating a liquid? What did you see when you cooled the test tube? What does this tell you about cooling a gas?

Can particles help us understand what happens during state changes?

I think the particles are the same, they just move differently No, there are different kinds of particle in solid candle wax and melted candle wax Gary I think the particles are the same, they just move differently David

In order to move particles need ENERGY Changing state When an object changes state- the particles all remain the exact same- they just move differently In order to move particles need ENERGY

Energy If particles are given more energy- they can move faster Take away the energy and the particles move slower

Solid to liquid Heating provides energy and particles move faster Particles in a solid move faster they can break free from solid and flow into a liquid Particles in a liquid have more energy and have moved apart from each other

Liquid to Solid Cooling a substance causes the particles to move slower Particles can no longer move freely- solid

Liquid to Gas Heating liquids provide enough energy for the particles to break free and leave the surface of the liquid They become a gas The particles are fast moving and have lots of space

Gas to Liquid Cooling the gas causes the particles to slow down Gas turns back to liquid

Evaporation and Condensation (copy) When a liquid is heated up, the particles gain more energy. They spread out and become a gas. This is called EVAPORATION. When the gas particles are cooled, they lose energy and get closer together. This is called CONDENSATION.