1. why an iron almirah is a solid at room temperature?
2. State the characteristics of matter demonstrated by: a)Diffusion     b)Brownian motion
3. Explain how the smell of food being cooked in kitchen reaches us even from considerable distance?
4. Explain why diffusion occurs more quickly in gas than in liquids?

1. An iron almirah is solid because:
(i) It has a fixed shape (which cannot be changed by pressing it with hands).
(ii) It has a fixed volume (which depends on the dimensions according to which it is made).

 

2. (a) Diffusion: 
(i) The matter is made up of tiny particles
(ii) The particles of matter are constantly moving.

(b) Brownian motion: 
(i) The particles of matter are very, very small.
(ii) The particles of matter are constantly moving. 

3. The smell of food being cooked reaches us even from a considerable distance is because of the process of diffusion.

 

4. Diffusion occurs more quickly in gases than in a liquid because the particles in gases move very quickly in all directions whereas the particles in liquids move slowly as compared to the gas particles.