Water: Purifying Water – Basic 3 Basic Science Lesson Note (Second Term)

Date: ___________
Class: Primary 3
Duration: 40 minutes

Basic science: water – purifying water

What is Water Purification?

Water purification means making dirty water clean and safe to drink. We remove harmful things from water.

Reasons for Purifying Water

We purify water to:

• Kill germs that make us sick
• Remove dirt and particles
• Make water safe for drinking
• Prevent diseases like cholera and typhoid
• Improve taste and smell
• Protect our health and our family’s health

Methods of Water Purification

Simple Methods at Home:

• Boiling – heat water until it bubbles for 5 minutes

• Filtering – pour water through clean cloth or sand

• Adding chemicals – use water purification tablets
• Settling – let dirty water sit so dirt goes to bottom

Other Methods:

• Chlorination – adding chlorine to kill germs
• UV treatment – using special light to kill bacteria
• Distillation – turning water to steam and back to liquid

Steps to Boil Water Safely

1. Put water in a clean pot
2. Cover the pot with a lid
3. Heat until water bubbles strongly
4. Let it boil for 5 minutes
5. Let it cool before drinking

Exercise 1:

1. Why do we purify water? _______
2. How long should you boil water? _______
3. Circle purification methods: Boiling / Swimming / Filtering / Dancing