Rate of Evaporation
These downloadable animations are part of the multimedia package Stuff and Substance, developed by the Gatsby Science Enhancement Programme (SEP). They can be used to develop ideas relating to the factors which affect the rate of evaporation and the particle model explanation.
The rate of evaporation (below boiling point) increases with surface area, with temperature and with strength of bulk air movement (breeze). Students accept these first two ideas quite readily but the effect of a breeze confuses some. They think a breeze slows down evaporation because of cooling - they do not appreciate that cooling is due to the increased rate of evaporation. One animation is a formative assessment task about the factors affecting evaporation. The other animation plays a particle representation of evaporation which can be used to explain why evaporation is affected by these factors (it includes the possibility of particles returning to explain the affect of a breeze). Questions to accompany this animation are given in the Stuff and Substance package.
These video and animation files form part of the resources in the section Evaporation in the Stuff and Substance multimedia package, which provides a series of interactive pages that can be used by teachers or students in the classroom.