Explain why, diffusion occurs more quickly in a gas than in al iquid.

Honey is more viscous than water. Can you suggest why?

Explain why:

(a) Air is used to inflate tyres.

(b) Steel is used to make railway lines.

(a) What is meant by ‘diffusion’? Give one example of diffusion in gases.

(b) Why do gases diffuse very fast?

(c) Name two gases of air which dissolve in water by diffusion. What is the importance of this process in nature?

(a) Compare the properties of solids, liquids and gases in tabular form.

(b) Give two reasons for saying that wood is a solid

During class, the students resemble molecules in a solid (because they are very close to one another)

While going from one classroom to another the students resemble molecules in a liquid (because they are a little more farther apart from one another)

And in the playground students resemble molecules in a gas (because they are very, very far apart from one another)