WALA: EVAPORATION

WALA: EVAPORATION

L.O: Know that evaporation occurs when a liquid turns into a gas.

INTRODUCTION

Review previous lesson on evaporation by asking oral questiions.

IMPORTANT POINTS TO NOTE

+ Evaporation happens when a liquid turns into a gas.

+ When particles of water gain heat energy, they move faster and Further apart and break free From the liquid's surface.

+ Heat makes evaporation takes place faster. 

TALK ABOUT

• Why does wet paint smell but dry paint doesn't?

• The liquid in the paint has a smell. When the liquid evaporates it becomes a gas. Our noses can smell the gas in the air. When the paint is dry, the smell disappears because all the liquid has evaporated.  

COMMON MISCONCEPTIONS

The most common misconception about evaporation is that the water disappears and does not exist any more, or that it changes into air or dries up and goes into the air. This is due the fact that learners cannot see where the water has gone. You will need to explain that the water evaporates, changing from a liquid to a gas.

ACTIVITY BOOK QUIZ

PAGE 23 NUMBER 1,2 AND 3

CONCLUSION ( Learners to mark their work)

• 1. Evaporation occurs when a liquid turns into a gas. The particles in the liquid gain energy and move faster and further apart until some of them escape from the surface and become a gas.

• 2. It evaporates so that the cement dries out.

• 3. The heat makes the water in the puddles evaporate faster than on cooler days because that the particles in the puddle gain heat energy which makes them move faster and further apart and change into water vapour more quickly