<p> Homework E1 What is a metal?</p><p>HELP </p><p>1 The list shows some properties of materials. </p><p> good electrical conductor insulator can be made into wires good thermal conductor breaks easily melts above 25 °C a Give three properties of metals. b Give two properties of non-metals. 2 Four uses of metals and reasons why they are used are shown below. Write down each use and match it to the reason for its use. </p><p>Uses Reasons</p><p>A Copper is used in electrical wiring 1 because it looks attractive and does not tarnish. B Mercury is used in thermometers 2 because it can be easily pressed into shape. C Gold is used for jewellery 3 because it expands a lot when it is heated. D Aluminium is used for drinks cans 4 because it conducts electricity very well.</p><p>CORE </p><p>3 a Draw a labelled diagram of the apparatus you would use to show that a metal was a good conductor of electricity. b What would you see, using your apparatus, if the following materials were tested? i plastic ii steel iii zinc iv carbon (graphite) 4 a What is true about all the atoms in a piece of tin? b Bronze is an alloy of copper and tin. How many types of atoms does a sample of bronze contain? </p><p>© Harcourt Education Ltd 2004 Catalyst 3 Sheet 1 of 2 This worksheet may have been altered from the original on the CD-ROM. Homework E1 What is a metal? (continued)</p><p>EXTENSION</p><p>5 The table shows the melting and boiling points of some metals. </p><p>Metal Melting point (°C) Boiling point (°C)</p><p>Tungsten 3377 5527</p><p>Sodium 98 883</p><p>Mercury –38 356</p><p>Lead 327 1740</p><p>Iron 1533 2750</p><p>Gold 1063 2707</p><p>Aluminium 660 2467</p><p> a i Which metal has the smallest temperature range as a liquid? </p><p> ii Which metal has the largest temperature range as a liquid? </p><p> b Give two reasons why tungsten is used in electric filament lamps. </p><p> c Lead forms part of electrical solder, used for joining wires. Explain why lead can be used for this purpose but mercury cannot. </p><p> d i Which metal will need the most energy, per million atoms, to boil it? </p><p> ii Explain your answer.</p><p>© Harcourt Education Ltd 2004 Catalyst 3 This worksheet may have been altered from the original on the CD-ROM. Sheet 2 of 2</p>