Evaporation

WALA : COMPARING EVAPORATION

L.O: to make predictions of what will happen based on scientific knowledge and understanding, and suggest and communicate how to test these.

REVIEW

Review the previous lesson

INTRODUCTION

Ask questions about the conditions in which washing dries best.

Get learners to suggest factors that will affect evaporation.

They will know that wind is one of the factors.

Get the learners to do the activity on the next slide

ACTIVITY

what you need.

1. Two identical containers.

2. Water

3. Permanent marker

4.A measuring jug

Check that learners are able to measure the volume of water correctly.

DO THE ACTIVITY ON THE NEXT SLIDE.

QUESTIONS

1. Was the water level in the two glasses the same after two days?

2. Which glass had the least water and which glass had the most water?

3. Why does washing dry quicker on a hot day?

EXPLANATION

Water can evaporate with the help of heat.

Changes in temperature can increase or decrease how fast water evaporates.

PLENARY

End the lesson by marking the questions

ANSWERS

• 1. NO

• 2. The glass in the cool place had the most water. It was cool, so not much water evaporated as the water particles did not absorb much heat. The glass in the warm place had the least water. The water particles were heated and had more energy than the water particles in the cool place so more evaporation took place.

• 3. The heat energy of the Sun makes the water evaporate quickly. Wind also helps washing dry.