S2 Chemistry Classifying chemicals and chemical reactions Alloys S2 Chemistry Classifying chemicals and chemical reactions

Learning outcomes Success criteria Know what an alloy is. You can define the term “alloy”. You can name three examples of alloys, naming the metals which make them up. Understand why alloys are useful. You can explain why making an alloy can be useful, using a specific alloy as an example.

Definition An alloy is “a mixture of metals with metals” or “a mixture of metals with metals and non-metals”. Alloys do not appear in the Periodic Table. Write down as many names of alloys as you can in one minute.

Iron, tin, copper, lead, zinc, manganese, carbon, nickel Name of alloy Components of mixture 1 2 3 Brass Bronze Cupro-nickel Solder Steel Complete the table to show the correct components of each alloy. Iron, tin, copper, lead, zinc, manganese, carbon, nickel

Why make alloys Alloys are made to combine useful properties of different metals. Gold is used in jewellery – why? Why is pure gold not used in jewellery? Gold is used in jewellery because it is unreactive, looks beautiful and is malleable. Pure gold is not used because it is too soft. Instead, gold is used in jewellery as an alloy (usually with copper or silver – this makes it harder). The purity is measured in karats.

Learning outcomes Success criteria Know what an alloy is. You can define the term “alloy”. You can name three examples of alloys, naming the metals which make them up. Understand why alloys are useful. You can explain why making an alloy can be useful, using a specific alloy as an example.