Comment on the statement 'Evaporation is a surface phenomenon'.

No heat is supplied to a liquid during evaporation. How does then the liquid change into its vapour?

Give reason for the increase in rate of evaporation of a liquid when:

(a) air is blown above the liquid.

(b) surface area of liquid is increased.

(c) temperature of liquid is increased.

What is boiling? Explain it on the basis of molecular motion.