5. Researching the properties of particular materials and understand why they are used for particular products.

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2 1. The difference between a physical and chemical change. 2. How to identify whether a physical or chemical change has taken place. 3. Understand what reactants and products are. 4. Writing and understanding chemical equations. 5. Researching the properties of particular materials and understand why they are used for particular products.

3 Involves this Fill in the missing words to describe what happens when states of matter change.

4 Evaporation Condensation

5 The difference between solid, liquids and gases can be described using this model. All matter is made up of particles. The particles are attracted to each other. There are bonds that hold the particles together depending if they are solid, liquids or gases. The particles are constantly moving. As temperature increases, the kinetic energy of the particles will increase too.

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9 1. The particles of matter are always. 2. When matter is heated, the particles move. 3. When matter is cooled, the particles move. 4. The particles of matter are held together by f which v in strength. 5. Particles in a solid simply. They are together. 6. Particles in a liquid can and past one another. 7. Particles in a gas move.

10 They are reversible. Think about water. You can make liquid water into ice by freezing it and then change it back into a liquid by heating it. No new substances are formed. Water will always by H₂O even when it is a solid, liquid or gas. The molecule will never change.

11 When an object changes state, shape or size, this is called a physical change. Physical changes are reversible. No new substance is formed.

12 Jump onto Edmodo and complete the worksheet assigned to you. Download it and then save it to your computer. THEN, you may complete it. Make sure you show Ms Wasif before you leave today!

13 If you finish early tell me what you think a chemical change is?

14 What was physical change again?

15 Melting, evaporation, condensation & freezing are all physical changes that are reversible and do not chemically alter the substance. A chemical change occurs when substances react chemically with one another to form new substances (new compounds) with different characteristic properties.

16 cooking rusting sticking burning making metals living!

17 Chemical reactions do not only happen in the laboratory. Chemical reactions happen anywhere that new substances are made. We describe them using word equations. Raw Egg Heat Cooked Egg cooking

18 burning Wood Oxygen Burning

19 Complete the series of experiments. WITH CARE!!! You must wear safety glasses at all times. Hair must be tied up and away from face. Ensure you hold the test tube away from you when heating! Use the test tube holders too!

20 What is this type of change and give me some example.

21 In a chemical reaction, more new substances are formed. The starting substances are called REACTANTS. The new substances formed are called PRODUCTS. REACTANTS PRODUCTS The arrow means change into. In a chemical reaction, All the reactants change into the products. It is difficult to reverse a chemical reaction and change the products back into the reactants.

22 A word equation is used as a quick, shorthand way of writing a chemical reaction. There are always three parts to a word equation: 1. The names of the reactants. 2. An arrow 3. The name of the products. What is the word equation for hydrogen reacting with oxygen to form water? hydrogen oxygen water

23 Chemical changes are usually difficult to reverse. Example: Magnesium burns in oxygen to form magnesium oxide. It is not possible to un-burn the magnesium once it has been burnt. magnesium oxygen magnesium oxide

24 In this chemical reaction, which substances are the reactants and which substances are products? magnesium copper oxide magnesium oxide copper Substance magnesium oxide magnesium copper oxide copper Reactant or Product? product reactant reactant product

25 What are the word equations for the following reactions? 1. Magnesium burns brightly with oxygen to form magnesium oxide. magnesium oxygen magnesium oxide 2. Calcium hydroxide reacts with hydrochloric acid to form calcium chloride and water. calcium hydroxide hydrochloric acid calcium chloride water 3. Sodium reacts with hydrochloric acid to form sodium chloride and calcium. sodium hydrochloric acid sodium chloride calcium

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27 A Chemical reaction is a chemical change in which a completely new substance is formed. Where s the evidence?

28 A PRECIPITATE appears in a liquid or gas. It is a cloudiness or a solid that forms when particular solutions are combined together.

29 An ODOUR may be released as a sign of a chemical reaction taking place. Compare and describe the smell of: a raw egg and a cooked egg fresh wood and burning wood a piece of bread and toast Can you think of anything else?

30 Bubbling/fizzing will occur when gases are released. Gases such as oxygen or hydrogen gas are released from some of the chemical reactions we have already done in class.

31 A chemical reaction will have taken place if the product becomes cooler or warms up.

32 When light is emitted (released) or a flame appears.

33 A simple colour change will also determine whether a chemical change has take place.

34 The only way to be certain that a chemical reaction has take place is to identify one or more new chemical products. 1. Magnesium burns brightly in oxygen to form magnesium oxide. magnesium oxygen magnesium oxide 2. Calcium hydroxide reacts with hydrochloric acid to form calcium chloride and water. calcium hydroxide hydrochloric acid calcium chloride water 3. Sodium reacts with hydrochloric acid to form sodium chloride and hydrogen. sodium hydrochloric acid sodium chloride hydrogen

35 If a chemical reaction has take place, you would have observed one or more of the following properties: Precipitate Odour Bubbles Temperature change Production of light Colour change New product formed