rusting - · pdf file9f keywords metal oxide tarnishing unreactive patina rusting corrosion a...
TRANSCRIPT
Can you match the word with the picture?
• rusting
• corrosion
• unreactive
• metal oxide
• tarnishing
• patina
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9F Keywords
metal oxide
tarnishing
unreactive
patina
rusting
corrosion
a compound containing only a metal and oxygen
a metal breaking down by reacting with oxygen (and sometimes moisture)
to gather a thin layer of discoloration by reacting with the air
describes a material that does not react
a thin layer of green on the surface of copper
the corrosion of iron, which reacts with oxygen and water to form flaky iron oxide
rusting corrosion
unreactive metal oxide
tarnishing patina
Starter: match the word to its meaning
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Aim • Explain what rusting is • Describe the conditions under which iron rusts Keywords • rusting • corrosion • unreactive • metal oxide • tarnishing • patina
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Only iron can rust
• Only iron and iron alloyes can rust
• Since steel is made of iron it can also rust
• The chemical name for rust is iron oxide
• Although other metals react with oxygen, their oxides are not called rust
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Set up an experiment with 4 iron nails
CONTROL Tube 1
Calcium chloride powder and bung
Tube 2
Boiled water with oil film and bung
Tube 3
Salty water
Look at the pictures carefully – your experiment should be set up just like this:
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iron oxide
oxygen + iron
Rusting Rusting is an ‘unhelpful’ chemical reaction but it is unfortunately very common. Rusting only occurs with the metal iron. It is the reaction of iron with oxygen in the presence of water to form iron oxide (rust).
2Fe2O3
3O2 + 4Fe
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Calcium chloride
powder and bung
Water and air Boiled water with oil film
and bung
Salty water
Use the internet to fill out these boxes
©cgrahamphysics.com 2016
Calcium chloride
powder and bung
Water and air
Boiled water with oil film
and bung
Salty water
Plenary: make your predictions
It will go slightly
rusty ©cgrahamphysics.com 2016
Key words • Rusting - the corrosion of iron, which reacts with
oxygen and water to form flaky iron oxide
• Corrosion -a metal breaking down by reacting with oxygen (and sometimes moisture)
• Unreactive - describes a material that does not react
• metal oxide - a compound containing only a metal and oxygen
• Tarnishing - to gather a thin layer of discoloration by reacting with the air
• Patina - a thin layer of green on the surface of copper
©cgrahamphysics.com 2016