Science at key stage 3    (Year 9)

• identify a range of fuels and describe fuels as substances that release energy when they burn
• generalise about the products of burning fuels that contain hydrogen and carbon
• balance advantages of hydrogen as a fuel, eg produces no carbon dioxide, light, against disadvantages, eg highly explosive if mixed with air, needs to be compressed for storage

• describe the role of the sulphur, carbon and potassium chlorate in the match head
• explain how the match produces a flame

• describe ways in which some chemical reactions can be used
• identify and explain differences between objective and more persuasive writing

• describe chemical reactions that are used to produce energy
• relate the energy produced to differences in reactivity, eg magnesium and copper are further apart in the reactivity series than iron and copper, so more energy will be produced

• name a range of materials in living and other systems resulting from chemical reactions
• describe the key stages of development of a new product

• identify the uses of particular chemical reactions
• describe the range of uses of chemistry in everyday situations

• devise a method of finding out whether mass is conserved in a reaction
• use models to describe the conservation of mass in a reaction
• use models or simulations to show how atoms combine in different ways as a result of a reaction

• recognise that mass is conserved in reactions in which gases are produced
• explain the apparent loss in mass in reactions involving the production of gases

• state that the mass of magnesium oxide is greater than the magnesium, and explain this in terms of combination with oxygen
• recognise the relationship shown in the graph, and use this to predict how much magnesium oxide will be made from other starting masses of magnesium

• state that carbon dioxide and water are formed when, eg wax, natural gas, is burned
• explain that the water and carbon dioxide formed escape into the air
• explain that if the carbon dioxide and water could be collected, there would be no loss of mass
• represent the reactions by word or symbol equations or diagrammatically
• identify from texts answers to questions posed
• summarise evidence about burning
• describe how eighteenth-century ideas about burning differ from those we hold today and summarise the evidence for present-day ideas

• match word equations to descriptions of reactions and/or symbol equations
• group together some reactions of a similar type
• identify key points about reactions