1. Matter Everything is made up of matter. There are 3 states of matter : SOLIDS, LIQUIDS and GASES.

2. Solids A solid cannot move. A solid keeps its shape. The volume of a solid always stays the same.

3. Liquids A liquid can flow. A liquid takes the shape of its container. The volume of a liquid stays the same.

4. Gases A gas can flow. A gas can change shape. A gas tries to fill its container

5. Kinetic Theory All matter is made up of tiny particles that are moving and have spaces in between them.

6. Spaces between particles 50 cm 3 alcohol+ 50cm 3 of water gives 97 cm 3 of mixture. Some of the small water molecules can fit into the big spaces between the large alcohol molecules.

7. Diffusion Diffusion occurs when particles of different substances move and mix with each other. Diffusion in gases happens quickest Diffusion in liquids is slower.

8. Particles in a solid The particles in a solid are very close together. Spaces between particles are very small. Can’t be compressed Particles are fixed in position and vibrate

9. Particles in a liquid Particles are slightly further apart than in solids but they are still touching each other. Particles are free to move. Particles are moving faster than in a liquid

10. Particles in a gas Particles are very far apart. Particles moving very fast.

11. Changing States Melting Add Heat Evaporation Add Heat Condensation Cool Freezing

12. Expansion and Contraction 1.The metal bar is longer when it is hot. 2.The bar is thicker when hot. 3.The particles vibrate more and the spacing between them increases. 4.When cooled the metal contracts to its original length

13. Expansion and Contraction Liquids expand more than solids and gases expand even more when heated. The particles in a gas ‘hold onto each other’ with the weakest force.

14. Atoms and Elements Everything is made from tiny particles called atoms. A substance that contains just one kind of atom is called an ELEMENT. Elements are the simplest substances and cannot be broken down into anything simpler. Oxygen, Hydrogen, Carbon, Iron, Copper, Gold and Silver are all examples of elements. An atom is the smallest particle of an element. An element contains only one type of atom An Element 14

16. Joining Elements Magnesium (Mg) is a solid metallic element. Oxygen (O) is a colourless, odourless gas. When Mg and O are combined the new substance formed is a white powder. The two elements magnesium and oxygen have combined to form a compound called magnesium oxide. An element is a substance that contains only one type of atom. A compound is a substance that contains several types of atoms joined together. 16

17. Mixtures and Compounds When iron and sulphur are mixed they remain separate atoms of iron and sulphur and can be easily separated using a magnet. When iron and sulphur react they combine to make a new type of substance called a compound. The compound is Iron Sulphide. + Atom of Iron Atom of Sulphur Molecule of the compound Iron Sulphide 17

18. A mixture of atomsAtoms of one element Molecules of one compound A mixture of molecules 18

19. Solvents and Solutions When a solid dissolves in a liquid it is said to be soluble. A liquid that dissolves a solid is called a solvent. A solid that dissolves is called a solute. If a solid does not dissolve it is insoluble. The solute fits into the spaces between t he solvent particles.

20. Saturated Solution. When dissolving salt in water there comes a point when no more salt will dissolve. When no more solute can be dissolved in a solvent we have a saturated solution

21. Gases of the Air

22. Neutralisation The pH of soil can be changed by adding an acid or alkali to it. If the soil is too acidic then an alkali such as lime can be added, this increases the pH. If the soil is too alkaline then an acid ( such as coffe grounds ) can be added to reduce the pH.

23. More neutralisation Bacteria in your mouth produce acid. This can cause decay. Toothpaste is alkaline which neutralises the acid. When you have an upset stomach your body has produced too much acid. Again this can be neutralised by an alkali.

24. Neutralisation Acid + Alkali Neutral substance

25. Acid Rain When fuels burn they release gases such as sulphur dioxide ( SO 2 ) and carbon dioxide ( CO 2 ). These gases dissolve in the water in clouds forming acids. This acid rain then falls on the earth.

26. Effects of Acid Rain Acid rain can destroy buildings by attacking the stone. It can kill plants and animals and it can reduce the pH of lakes and rivers.

27. Global Warming Some gases such as methane, carbon dioxide and water vapour act like a blanket. This extra layer of insulation stops some of the heat escaping into space. This causes the earth’s temperature to rise.

28. Effects of global warming Ice caps are melting Weather is becoming extreme Plants and animals are dying out and new ones are taking their place

29. Where do the gases come from? Carbon Dioxide is released when fossil fuels are burned and when animals breathe out. Methane is released when rubbish decays and by animals. Water vapour is released when animals breathe out and when fossil fuels burn.

30. Carbon Capture Our carbon footprint depends on our lifestyle : Do we : recycle ? use public transport / cycle or our own car ? waste electrical energy ? Some things are beyond our control e.g streetlights, school heating and so on.

31. Carbon capture A big source of ‘carbon’, really carbon dioxide, is when we burn fossil fuels. Scientists and engineers are investigating ways of capturing and storing this gas.