Ravi added a small amount of common salt to water taken in a graduated cylinder. On dissolution, there was no detectable change in the level of water. Explain why is it so?

Give the main points of difference in the three states of matter in the tabular form.

What is meant by 'diffusion'? Give one example of diffusion in gases.

Why do gases diffuse very fast ?

Name two gases of air that dissolve in water by diffusion. What is the importance of this process in nature?

Why does a gas fill a vessel completely ?

Why are gases so easily compressible whereas it is almost impossible to compress a solid or a liquid ?

What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain) during Brownian motion.