Year 7 Science
Materials and their Properties
Lesson 3
Choosing the Right Material
Which Clothes Today?
This morning you may have made a choice about which clothes you were going to wear. Something warm if the weather is cold, a waterproof coat if it is raining. You may not have realised it at the time but the properties of the materials may have been important in helping you make your decision.
A fleece jacket. Good at keeping you warm
A cotton T-shirt. Good at keeping you cool
To save on washing some manufacturers have made clothes from paper. Paper underwear is still popular.
What problems might you have if all your clothes were made from paper?
What properties of paper might be useful for making clothes?
Activity 1 - Which property?
Above are some example of properties. You can probably think of some more.
For each material or object below choose what you think is its most useful property.
Next think of a use that makes the most of that property. One example has been completed for you.
Material/Object
Property
Uses
Gold
Shiny
Jewellery
Rubber
Plastic bucket
Sugar
Safety glasses
Aluminium foil
Cotton wool
Nylon thread
Iron nail
Sandpaper
Coin
Sellotape
Activity 2 - Which material?
Now try it the other way round. Which material would you use and why if you were going to make the following objects. The reason is likely to have something to do with the materials property.
Object
Material
Most Useful Property
Table Window Shoebox Electrical Wire Paving Slab Bottle Bicycle tyre Saucepan
Choose three objects and think of the worst material you could use. Give your reasons.
Activity 3 - Keeping Warm
Some students carried out the following experiments in order to find out which material was the best at keeping something or somebody warm.
They wrapped different materials around boiling tubes of hot water and recorded the temperature at regular intervals.
What should they do to make sure that their experiments are all fair tests?
Click here for answers. (Only after you have worked out your own)
The materials they tried were:
Cotton wool
cardboard
shredded paper
Which one do you think would be the best?
Here are their results.
Cotton Wool
Cardboard
Shredded Paper
Time (min) Temperature (degrees Celsius) Time (min) Temperature (degrees Celsius) Time (min) Temperature (degrees Celsius) 1 80 1 80 1 80 2 70 2 69 2 70 3 61 3 59 3 60 4 53 4 50 4 52 5 44 5 42 5 43 6 38 6 34 6 37 7 35 7 31 7 34 8 33 8 29 8 32 9 32 9 28 9 31 10 31 10 27 10 30
Try one of the following:
Draw a bar chart for each of the materials.
Draw a line graphs for each set of results using the same axis. See below.
Compare your line graphs or bar charts.
Which material would you use to line a jacket that you would wear in cold weather?
Can you think why this material is the best of the three?
Are there any disadvantages to using this material?
Remember properties are important. What you can do with a material depends upon its properties.
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