Question

Give reasons for the following observations. 

(a) Naphthalene balls disappear with time without leaving any solid. 

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

Answer 1

(a) Naphthalene shows the property of sublimation. Evaporation of naphthalene takes place easily and so it disappears during course of time without leaving a solid. 

(b) Perfumes vaporize very fast and its vapours diffuse into air easily. That is why we can smell perfume sitting several meters away.