Page 148 - Science Coursebook

10.4 Conductors and insulators

Most houses and other buildings have electricity.
There are wires hidden in the walls and under the
floors which carry electricity to where it is needed.

These wires are made of a metal, copper – that is the
part that carries the electricity. The metal is covered
with plastic – this makes sure you do not get a shock
if you touch the wire.
Metals are described as conductors because they
allow electricity to pass through them. Plastic and
other non-metals are described as insulators – they
do not allow electricity to pass through them. Wires like these are used to carry electricity
around a building.

Activity 10.4
Metals and non-metals

SE You can use the circuit shown to test whether materials are conductors or insulators.

Use the clips to connect onto the ends of a piece of metal, plastic or other material.
If the lamp (bulb) lights up, the material is a conductor.

1 Test some different materials. Divide them into conductors and insulators. Can
you find a non-metal that conducts electricity?

2 Some metals are better conductors than others. Use the circuit to put your metal
samples in order, from best conductor to worst conductor.

Testing a piece of aluminium foil.

Question
A1 In the photograph, a piece of aluminium foil is being tested. Is aluminium a
conductor? Explain how you can tell.

146 10 Electricity

A+E