Hi there, young learners! Welcome back to Basic Science & Technology, Primary 4. In our previous lesson, we learned about the Water Cycle – Dew. Today, we’re going to learn about the chemical composition of water.
Objectives
By the end of this lesson, you should be able to:
- Understand the chemical composition and formula of water.
- Appreciate the importance of water in daily life and its unique composition.
- Identify and write the chemical formula of water.
Chemical Composition of Water
What is water made of? Water is a special substance that we need to survive. It’s not just a simple liquid; it’s made up of smaller parts called elements. These elements are like building blocks that combine to form water.
What is H2O?
The chemical formula for water is H2O. This tells us what elements water is made of and how much of each element is present.
- H stands for hydrogen. Hydrogen is a colorless, odorless gas that is the lightest element.
- O stands for oxygen. Oxygen is a gas that we breathe and is essential for life.
- The number 2 next to the H means that there are two hydrogen atoms for every one oxygen atom in a water molecule.
Subtopic 1: The Water Molecule
Imagine a tiny, tiny particle called a molecule. This molecule is the smallest unit of water. It’s so small that you can’t see it even with a powerful microscope!
- Each water molecule is made up of three atoms: two hydrogen atoms and one oxygen atom.
- These atoms are connected like a tiny triangle, with the oxygen atom at the top and the two hydrogen atoms at the bottom.
Subtopic 2: Why is Water Important?
Water is essential for all living things. Some of the reasons why water is so important include:
- Drinking: We need water to stay hydrated and keep our bodies functioning properly.
- Growing: Plants need water to grow and produce food.
- Cleaning: Water is used for cleaning our bodies, homes, and clothes.
- Cooling: Water helps to cool down our bodies and the environment.
Evaluation Questions
Now that you’ve learned about the chemical composition of water, let’s see if you can answer these questions:
- What is the chemical formula of water?
- What two elements make up water?
- How many hydrogen atoms are there in one molecule of water?
- Why is water important for living things?
- Can you draw a simple diagram of a water molecule?
Conclusions or Summary
Today, we learned that water is a compound made up of two elements: hydrogen and oxygen. The chemical formula for water is H2O, which means there are two hydrogen atoms for every one oxygen atom in a water molecule. Water is essential for life and plays a vital role in many aspects of our world.
Don’t forget to check the comments section if you have any questions, and use the navigation to move to the next lesson. See you in the next lesson!
