1. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Evaporation and condensation: overview

2. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Look at this puddle. Eventually it will dry up. What is the process by which this happens called? Evaporation

3. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Evaporation Use the kinetic theory to explain the process of evaporation as the puddle dries up.

4. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Evaporation The heat from the Sun adds thermal energy to the puddle. The puddle heats up and the particles with the highest energy escape. Eventually this process will cause all the particles to escape and the puddle dries up.

5. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Evaporation Can you think of three ways to increase the rate of evaporation? 1Increase the flow of air over the surface of the liquid. 2Add thermal energy by heating the liquid. 3Increase the surface area of the liquid.

6. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Look at this glass of cola. Water droplets have formed on the outside of the glass. What is the process by which this happens called? Condensation

7. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Condensation Use the kinetic theory to explain the process of condensation as the water droplets form on the outside of the glass.

8. © Oxford University Press 2011 IP1.5.7 Evaporation and condensation: overview Condensation Water vapour in the air is cooled down by the cold glass. The vapour particles lose energy and condense into water droplets on the outside of the glass.