UNIT 2: AIR
In activity 1 we read that we cannot see the air around us. Pure air is therefore said to be
colourless.
(a) What would happen if air had a colour?
Discuss in your groups and write a sentence about it.
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We nd that if air had a colour, we would not be able to see clearly around us. We would
therefore nd it dicult to nd our way. We would not be able to identify the colour of
owers and of rainbows.
Thus, it is a good thing that air is colourless.
So one of the properties of pure air is that it is colourless.
Now let us learn about some other properties of pure air.
Certain things have a pleasant smell. Others have an unpleasant smell.
Observe Figure 4 and answer the questions.
Figure 4 - Pleasant and unpleasant smells
Pleasant smell Unpleasant smell
Activity INVESTIGATING THE
PROPERTIES OF AIR
2
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