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Science C1 Topic 4
GCSE edexcel core science chemistry: metals
Question | Answer |
---|---|
How are metals like gold found in the earth's crust? | They are found naturally as elements as they are unreactive. |
What is an ore? | An ore is a rock that contains a meatl compound in e.g. bauxite |
How can you extract unreactive metals? What is an example of a metal that this can be done with? | By heating them with carbon- the carbon gets oxidised to form carbon dioxide and the metal compound gets reduced to leave the metal as an element e.g. iron |
How can you extract more reactive metals? What is an example of a metal that this can be done with? | By using electrolysis- but they have to be molten or as a solution e.g. aluminium |
Iron oxide + carbon -> ? (extraction) | carbon dioxide + iron |
Aluminium oxide -> ? (extraction) | aluminium+ oxygen |
Is it easier or harder to extract a very reactive metal? | Harder (and more expensive) |
What is oxidation? | The gain of oxygen/ when oxygen is added to a substance |
What is reduction? | The loss of oxygen / when oxygen is removed from a substance |
What other process does oxidation lead to? | Corrosion |
Does a more reactive metal corrode more slowly or more quickly? | Quickly |
What is the recycling of metals? | When metals are melted down and made into something new |
What are some advantages of recycling metals? | * Natural reserves of metals will last longer * It saves energy, as it requires less than the extraction of ores- making it cheaper * There is less pollution * Less waste metals in landfill sites * Reduces the need for mining, which causes noise pollu |
What are some disadvantages of recycling metals? | * It is expensive to collect, transport and sort the metals for recycling * Sometimes it can be more expensive to recycle metals |
What is an advantage of steel and iron being recycled in particular? | As they are magnetic, they can easily be separated from the other metals |
What are some properties of metals? | - Malleable - Good heat conductors - Good electrical conductors - Ductile - Usually solid at room temperature |
What is a property and use of aluminium? | It has a low density and is light- so is used to make aeroplanes, as the lighter the aeroplane is, the less fuel it will need to fly |
What are some properties and uses of copper? | 1) It doesn't react with water so is used in water pipes 2) It is a good conductor of electricity so is used for electrical wires |
What are some properties and uses of gold? | 1) It doesn't corrode and is attractive so is good for jewellery |
What is a property and use of steel? | Steel is very strong so is used to make machinery and building frames |
What is an alloy? | A mixture of metals (and sometimes carbon)that create a new metal with specific desired characteristics |
Why are alloys stronger than pure metals? | In a pure metal element, atoms are all the same size, therefore they easily slide over each other in layers when a force is applied. But in an alloy, the different sized atoms jam up the structure so that the layers do not slide over each other so easily |
Why is gold alloyed? | Gold is naturally very soft so is alloyed with other metlas such as copper and silver to make it stronger so it can be made into jewellery |
How is the purity of gold measured? | In carats (out of 24) and in fineness (out of 1000) |
What is nitinol and what are its uses? | It is a shape memory alloy made of nickel and titanium, which can be used to repair a collapses artery and for flexible spectacle frames |
What is a smart material? | A material thats properties change with a change in conditions |
What is a shape memory alloy? | An alloy which returns to its original shape when heated |