PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Metals © 2021 Marshall Cavendish Education Pte Ltd The following content has not been through the Cambridge Assessment International Education endorsement process. 1 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Metals and Their Properties How are the physical properties of metals and non-metals different? • Metals have higher melting points and are Metals stronger than non-metals because the particles in metals are held together more strongly. Comparing the physical properties of metals and non-metals © 2021 Marshall Cavendish Education Pte Ltd 2 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Chemical reactions of metals What are the chemical properties of metals? Most metals react with acids, water and oxygen to give similar products. Reaction of zinc with dilute hydrochloric acid Reaction of magnesium with cold water © 2021 Marshall Cavendish Education Pte Ltd Reaction of magnesium with oxygen 3 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Uses of Metals The uses of metals depend on their properties. Every metal has its unique properties. What are the uses of aluminium? • Pure aluminium reacts with oxygen in the air to form a very thin layer of aluminium oxide. • This layer prevents aluminium from reacting further with oxygen and water Physical properties of aluminium © 2021 Marshall Cavendish Education Pte Ltd 4 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book What are the uses of aluminium? (continued) Different uses of aluminium © 2021 Marshall Cavendish Education Pte Ltd 5 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book What are the uses of copper? • Copper is a very unreactive metal and corrodes very slowly. • When copper corrodes, a green layer is formed on its surface. • The green layer prevents copper from being corroded further. Physical properties of copper © 2021 Marshall Cavendish Education Pte Ltd 6 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book What are the uses of copper? (continued) Different uses of copper © 2021 Marshall Cavendish Education Pte Ltd 7 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Alloys and Their Properties An alloy is a mixture of a metal with other elements. Why are metals often used in the form of alloys? Alloys are stronger and do not wear away easily. Why metals are often used as alloys © 2021 Marshall Cavendish Education Pte Ltd 8 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Examples of alloys, their compositions, properties and uses Note: Percentages of metals may vary in each alloy. © 2021 Marshall Cavendish Education Pte Ltd 9 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book How is the structure of an alloy different from that of a pure metal? What are the differences between the two structures? Structure of a pure metal © 2021 Marshall Cavendish Education Pte Ltd Structure of an alloy 10 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Better bicycles • Iron or steel? • Pure iron – soft, not very strong • Steel (iron + carbon) – strong, bends instead of breaking © 2021 Marshall Cavendish Education Pte Ltd PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Better bicycles – Alternative alloys Property Titanium alloy Aluminium alloy density, g/cm3 4.4 2.7 relative hardness 334 30 strength, MN/m2 950 124 fatigue strength, MN/m2 240 62 melting temperature, oC Up to 1660 Up to 652 the higher the density, the heavier the bike for its size the pulling force that breaks 1m2 of the alloy the smallest force that can damage the alloy the lower the melting temperature, the cheaper the metal is to melt when making the frame © 2021 Marshall Cavendish Education Pte Ltd 12 PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book Better bicycles – Other materials Carbon fibre reinforced polymer (CFRP) • lightweight • smooth to ride Bamboo • durable • strong • sustainable © 2021 Marshall Cavendish Education Pte Ltd PowerPoint Slides for Cambridge IGCSETM Chemistry Student’s Book What have you learnt? © 2021 Marshall Cavendish Education Pte Ltd
