Do all the molecules of a liquid take part in evaporation ? If not, explain your answer.
No, all the molecules of the liquid do not take part in evaporation only those molecules near the surface of liquid which acquire sufficient Kinetic energy (Threshold velocity) escape as they over come attractive forces of other molecules. Then other molecules come to the surface of the liquid and acquire more K.E. and escape the surface. This continues till all the liquid evaporates.