PRIMARY 3: BASIC SCIENCE – SECOND TERM | WEEK 6

TOPIC: PURIFICATION OF WATER

A: TEACHING AND LEARNING MATERIALS

1. Dirty water sample.
2. Clean water sample.
3. Filter cloth.
4. Funnel.
5. Clean container.
6. Alum sample or picture.
7. Pictures showing boiling of water.
8. Pupils’ notebooks and pencils.

B: REFERENCE MATERIALS

1. Scheme of work.
2. Recommended Basic Science textbook for Primary 3.
3. Online educational resources.

C: PREVIOUS KNOWLEDGE

The pupils have learnt the qualities of clean water, causes of water contamination and the dangers of drinking unsafe water.

D: PERFORMANCE OBJECTIVES

By the end of the lesson, pupils should be able to:

1. Explain water purification.
2. State reasons for purifying water.
3. Mention methods of purifying water.
4. Describe filtration and boiling.
5. State how purified water should be stored safely.

E: CONTENT

Meaning of Water Purification

Water purification is the process of making water cleaner and safer for use. Water from unsafe sources may contain dirt and germs.

Reasons for Purifying Water

We purify water to:

1. Remove dirt.
2. Reduce harmful germs.
3. Make water safer for drinking.
4. Prevent some water-related diseases.

Methods of Purifying Water

Methods include:

1. Boiling.
2. Filtration.
3. Use of approved water-treatment chemicals.
4. Sedimentation.

Boiling

Boiling water can kill many harmful germs. 🔥 + 💧 ➡️ boiled water Boiled water should be allowed to cool in a clean, covered container. Children should not handle boiling water without adult supervision.

Filtration

Filtration removes some solid dirt from water. A clean cloth or filter can be used to separate visible dirt. Filtering alone may not remove all germs, so drinking water may still need further treatment.

Use of Alum

Alum can help small particles of dirt gather together and settle. The clearer water above can then be carefully separated and further treated.

Safe Storage

Purified water should be:

1. Kept in a clean container.
2. Covered properly.
3. Protected from dirty hands and cups.
4. Stored away from waste and chemicals.

F: LESSON PRESENTATION

F1: Teachers’ Activities

1. Revises water contamination.
2. Explains water purification.
3. Demonstrates simple filtration.
4. Explains boiling as a purification method.
5. Shows or explains the use of alum.
6. Discusses safe water storage.

F2: Pupils’ Activities

1. Explain water purification.
2. Mention reasons for purifying water.
3. Observe filtration.
4. Mention methods of water purification.
5. Describe safe storage of water.
6. Answer oral questions.

G: CONCLUSION

The teacher explains that water should be properly treated and stored safely before drinking when its safety is uncertain. Pupils are reminded not to drink water from dirty or unknown sources.

H: EVALUATION GUIDE

Pupils should be able to answer the following questions:

1. What is water purification?
2. Why do we purify water?
3. Mention three methods of water purification.
4. What does filtration remove from water?
5. What can boiling do to many harmful germs?
6. How should purified water be stored?
7. Should children handle boiling water without an adult?