Question

Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.

Answer 1

(a) Naphthalene balls disappear with time without leaving any solid because of they undergoes sublimation easily i.e., the change of state of naphthalene from solid to gas takes place easily
(b) Perfumes have high degree of vaporisation and its vapour diffuses into the air easily. Therefore we can get the smell of perfume sitting several metres away.