Week Eight
Subject: Basic Technology
Week of Third Term: 8th Term
Class: Primary Five
Topic: Magnetism
Subtopic: Definition of Magnetism, Properties of Magnets
Objectives
At the end of the lesson, pupils should be able to:
- Define magnetism and describe how it works.
- Identify and explain the properties of magnets.
- Demonstrate the attraction and repulsion properties of magnets through practical activities.
Entry Behaviour
Before starting this lesson, pupils should already know:
- Basic understanding of objects and materials that attract or repel each other.
- Knowledge of the Earth’s magnetic poles and basic physical concepts (e.g., attraction and repulsion).
Instructional Materials
- Bar magnets
- Compass
- Iron filings
- Chart of magnetic poles
- Magnet diagrams
- Video on magnetism
Reference Materials
- Ijiyemi, C. (2016). Foundations of Science & Technology for Primary School Book 5. Metropolitan Publishers: Lagos.
- Oyinlola, M., Rahaman, B., & Ezeume, I. (2015). Basic Science and Technology for Primary School Book 5 (Bec Edition). Spectrum Book Limited: Lagos.
Content
What is Magnetism and How Does It Work?
Magnetism: Magnetism is a force that can attract or repel certain materials, especially metals like iron and steel. It is a natural force that acts over a distance without touching the objects. You can think of magnetism as an invisible power that makes magnets do things like attract paper clips or make compass needles point north!
How Does Magnetism Work?
Magnetism works because of tiny particles called atoms. Every atom has electrons that move around the nucleus, creating a very small magnetic field. In some materials, like iron, these tiny magnetic fields all line up in the same direction, creating a stronger and larger magnetic field that we can see and feel.
- North and South Poles: Every magnet has two ends, called poles. These are the areas where the magnet’s magnetic force is the strongest.
- The north pole of a magnet will attract the south pole of another magnet.
- The south pole of one magnet will attract the north pole of another magnet.
- Like poles (north-north or south-south) will repel each other.
In simple terms, opposite poles attract, and like poles repel!
2. Properties of Magnets
Magnets have some special properties that make them unique.
1. Attraction and Repulsion
- Attraction: A magnet will attract materials like iron, steel, and nickel. For example, a magnet can pick up paper clips or a nail made of iron.
- Repulsion: When two magnets have the same poles facing each other (like north-north or south-south), they will push away from each other, or repel.
2. Magnetic Poles
- Every magnet has two poles: the north pole and the south pole. These poles are the strongest parts of a magnet.
- If you break a magnet in half, you will get two smaller magnets, each with its own north and south pole. This shows that a magnet always has both poles, no matter how many pieces you cut it into.
3. Attracts Certain Materials
- Magnets can attract certain materials, like iron, steel, nickel, and some other metals. But they do not attract wood, plastic, or rubber.
- Magnetic materials are metals that have special properties that allow them to be attracted to a magnet.
4. Magnetic Field
- The area around a magnet where its magnetic force can act is called the magnetic field. You can’t see this field, but you can feel its effects.
- You can visualize a magnetic field by using iron filings. If you sprinkle iron filings around a magnet, they will arrange themselves in patterns that show the shape of the magnet’s field.
5. Strength of a Magnet
- The strength of a magnet depends on how strong the magnetic field is. Larger magnets usually have a stronger magnetic field.
- The closer a magnet is to an object, the stronger its effect will be. So, magnets work best when they’re close to the material they attract.
6. Magnetism Can Be Temporary
- Some materials can become temporarily magnetized. For example, when a piece of iron is rubbed with a magnet, it can become a temporary magnet. But if you take the magnet away, the iron will lose its magnetism.
- Permanent magnets keep their magnetism for a long time, like the magnets on your refrigerator.
Lesson Presentation (Step-by-Step Procedure)
Step 1: Introduction
Begin by showing the class a bar magnet. Ask the pupils if they have ever used a magnet and what happens when they bring two magnets close to each other. Explain that today they will learn about the force called magnetism.
Step 2: Explanation
Define magnetism and explain how it works. Show the pupils that magnets attract certain materials and discuss the two types of poles: north and south. Highlight that opposite poles attract while like poles repel. Use a compass to show how the magnetic needle always points north, demonstrating the concept of magnetic poles.
Step 3: Demonstration
- Hold up two bar magnets and show how the same poles (north-north or south-south) repel each other, while opposite poles (north-south) attract.
- Use iron filings to show the magnetic field of a magnet. Place a sheet of paper over a magnet, sprinkle the filings on the paper, and observe how the filings align themselves along the magnetic field lines.
Step 4: Guided Practice
In pairs, have the pupils use a compass and a bar magnet to observe the poles of the magnet and identify the direction of the magnetic field. They should experiment with attracting and repelling magnets by bringing like and opposite poles together.
Step 5: Independent Practice
Ask the pupils to complete the following:
- Draw a magnet with labeled poles (north and south).
- Describe the properties of magnets and show how the poles work in attracting and repelling each other.
Step 6: Feedback
Walk around and assess pupils’ diagrams and understanding. Provide feedback and correct misconceptions. Ask pupils to demonstrate the magnetic properties using their magnets.
Evaluation
Formative Assessment:
- Ask pupils, “What happens when you bring two magnets with the same poles together?”
- Observe pupils as they work with the compass and magnets to ensure they are correctly identifying the poles and understanding the concept of attraction and repulsion.
Summative Assessment:
- At the end of the lesson, ask pupils to:
- Define magnetism.
- Explain at least two properties of magnets.
- Describe what happens when like and opposite poles of magnets are brought together.
Summary/Conclusion
Summarize the key points of the lesson by reviewing the definition of magnetism and its key properties (attraction and repulsion, polarity, magnetic field, and attraction to magnetic materials). Emphasize that every magnet has two poles, and like poles repel while opposite poles attract.
Assignment
For homework, ask pupils to:
- List three materials that are attracted to magnets.
- Draw a diagram of a magnet with its magnetic field lines using iron filings.