Question

Give reasons to justify:



a.Moth balls disappear with time without leaving any solid.



b.We can get the smell of perfume several meters away

Answer 1

Answer:

(a) Naphthalene balls undergo sublimation due to which it converts directly into vapours and disappear into air without leaving any solid. (b) The particles of perfume diffuse rapidly into the air and its smell can be felt while sitting several metres away.

Answer 2

Answer:

We can get the smell of perfume several metres away because of the diffusion of perfume particles

Diffusion is the process by  which particles move from higher concentration area to lower concentration area