Summary C5: Chemical Changes

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C5 Chemical Changes
C5.1 - The Reactivity Series

Ores: the rocks/raw materials from which valuable metals are extracted from
❖ most metals found in ores have been oxidised (eg. iron oxide, aluminium oxide)
and so to extract the pure metal from the oxide, the compound must be reduced
(have the oxygen removed)
❖ this is the reactivity series, the most reactive being at the top:




❖ reacting with water:
➢ the first four most reactive elements fizz and give off hydrogen gas
➢ the second four have very slow fizzing reactions
➢ the last two have the slightest reaction with steam
❖ reacting with dilute acid:
➢ the first three explode
➢ the following five give off hydrogen and produce a salt
➢ the last two react slowly in warm acid

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❖ the elements under hydrogen have no reaction at all when exposed to water or
dilute acid




❖ the acronym “oil rig” helps us to remember what happens when something is
oxidised/reduced in terms of electron movement
➢ displacement reactions are known as “redox reactions” as both oxidation
and reduction takes place