1 the List Shows Some Properties of Materials

Homework E1 What is a metal?

1 The list shows some properties of materials.

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.

Uses Reasons

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.

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?

EXTENSION

5 The table shows the melting and boiling points of some metals.

Metal Melting point (°C) Boiling point (°C)

Tungsten 3377 5527

Sodium 98 883

Mercury –38 356

Lead 327 1740

Iron 1533 2750

Gold 1063 2707

Aluminium 660 2467

a i Which metal has the smallest temperature range as a liquid?

ii Which metal has the largest temperature range as a liquid?

b Give two reasons why tungsten is used in electric filament lamps.

c Lead forms part of electrical solder, used for joining wires. Explain why lead can be used for this purpose but mercury cannot.

d i Which metal will need the most energy, per million atoms, to boil it?

ii Explain your answer.