AI Tutor - Lucy
The various materials that are used in building is one of the topics covered in GCSE Science. This is the sixth of seven quizzes on that particular subject and it looks specifically at the different physical properties of metals and suitable uses that can be found for them.
It is hard to imagine life without metals. They are strong and can be bent, beaten and stretched into shape without breaking. They also conduct both heat and electricity. Some of the less reactive metals can be found 'native' but the majority are obtained as ores. Ores are naturally occurring rocks that provide an economic starting point for the manufacture of metals. Iron ore is used to make iron and steel. Some metals, for example copper, can be easily extracted whilst others are more difficult. Our metals come from the crust of the Earth and will one day run out - they are non-renewable.
[readmore]Different metals have different properties and so are suitable for different tasks. The uses of metals are linked to both their chemical and their physical properties. Copper conducts electricity extremely well and is soft - therefore, one of the uses it is most suitable for is as electrical wires. Although it is soft, it is hard enough to be used for plumbing and is an improvement on the original material, lead, as it does not react with water. It is not used for the cables that carry the electricity of the national grid - aluminium is used for that purpose as it is much lighter than copper. Most metals expand and contract by large amounts as they become hotter and cooler which is why the cables used for the national grid are slack. If they were tight, in the winter, they would contract, stretch and become weakened.
An interesting use of the expansion and contraction of metals is in bimetallic strips. These rely on the fact that different metals and alloys expand and contract by different amounts. When pieces of the same length of two different types of metal are joined firmly together, when the strip is heated or cooled, it will bend towards the metal that expands the least. This makes it useful for devices such as thermostats. Bimetallic strips are also used to make some types of thermometer and can even be used in analogue clocks and watches to help to regulate them as temperatures change.
Take this quiz to see how well you understand the physical properties of metals and how these affect their possible use.
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You can find more about this topic by visiting BBC Bitesize - Metals and alloys - AQA
Corrosion resistance is a chemical property
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When they are alloyed with aluminium, they form light but extremely strong alloys
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There are several reasons but one of the important ones is that cables carrying electricity in the National Grid need to be large and therefore will be heavy. Using a low density metal like aluminium keeps the weight down as far as possible
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Cast iron is too brittle and would break, copper is too soft and titanium would be too expensive
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Titanium alloys are particularly of interest to racing cyclists who need tough, reliable and lightweight parts for their bikes. The melting point is of no concern to them at all!
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A car body needs to be able to protect the occupants and to be easy to shape
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Tungsten isn't one of the metals that you are required to know about but the examiners will often throw in questions about materials that you don't know. They are testing to see if you can make logical choices using what you know about the physIcal properties of metals being linked to their uses
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Water pipes are buried in the ground. Copper is a very good electrical conductor. Putting the two together makes a good way of providing an earthing system for older houses in particular. In newer houses that use plastic for the plumbing, a different system is used
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Some of the atoms in a metal lose an electron from their outermost energy level (shell) and these are free to move through the structure. Electricity is a flow of electrons
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We say metals are ductile (can be pulled into shape) and malleable (can be hammered or bent into shape)
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