Topic 11: Metals

Introduction

Pupils should be encouraged to identify the presence and use of metals in the world around them. The social and industrial importance of the metal industry should be discussed, including the finite nature of metal sources and the need for re-cycling. Pupils should be aware that over three-quarters of the chemical elements are metals; this topic deals with some properties, uses and reactions of the more common metals and considers why some are found uncombined while others have to be extracted from ores.

At General Level, the Learning Outcomes are based on:

  • some understanding of the macroscopic features of metal chemistry
  • an awareness of the idea of reactivity in metals
  • knowledge of ways of extracting metals from ores
  • knowledge of the changes brought about by alloying.

At Credit Level, in addition, the Learning Outcomes require knowledge that some metal oxides can be reduced by heating with other substances; the ability to carry out calculations involving percentage composition.

Topic 11: Metals Learning Outcomes

GENERAL LEVEL (Grades 4, 3) CREDIT LEVEL (Grades 2, 1)

Pupils should be able to: and in addition to:

1 State that metals conduct electricity when

solid or liquid

2 Relate specific properties of metals, eg

density, thermal and electrical conductivity,

malleability, strength, to their uses

3 Explain the need for recycling metals in

terms of the finite nature of the metal

resources

4 Describe the reactions of different metals

with oxygen, water and dilute acid

5 State that these reactions give an

indication of the reactivity of the metal

6 State that ores are naturally-occurring

compounds of metals

7 State that the less reactive metals are

found uncombined in the earth’s crust and

that the more reactive metals have to be

extracted from ores

GENERAL LEVEL (Grades 4, 3) CREDIT LEVEL (Grades 2, 1)

8 Explain that the extraction of a metal

from its ore is an example of reduction

9 Explain why the inactive metals were

among the first to be discovered

10 Give examples of social and industrial

factors which resulted in large scale

extraction of more reactive metals

11 State that some metals can be obtainedExplain in terms of reactivity of the

from metal oxides by heat alone; some bymetal why some metals can be

heating with carbon; and some need otherobtained from the metal oxides by heat

methodsalone; and why some metal oxides need to be heated with other substances,

eg carbon or carbon monoxide; and

why some metals cannot be obtained by

these methods.

12 State that iron is produced from iron ore in

the blast furnace

13 State the two key reactions which take

place in the blast furnace:

  • production of carbon monoxide
  • reduction of iron oxide

14 State that an alloy is a mixture of metals

or of metals with non-metals

15 Give examples of the important uses of

alloys, eg brass, solder, “stainless” steel

16 Work out empirical (or molecular)

formulae from masses or

percentage composition

17Work out percentage masses of

elements in compounds from their names or formulae