Week Two
Subject: Basic Technology
Class: Primary Three
Week of the Third Term: 2nd Week
Subtopic: Properties of Energy
Sub-subtopic: Energy Cannot Be Created or Destroyed, Energy Can Be Converted
At the end of the lesson, pupils should be able to:
- Explain the law of conservation of energy (energy cannot be created or destroyed).
- Describe examples of energy conversion (e.g., electrical to heat energy).
- Demonstrate an understanding of energy conversion using simple classroom examples.
Entry Behaviour
Before starting this lesson, pupils should already know:
- The concept of energy and its uses (e.g., light, heat, and mechanical energy).
- Basic examples of energy in everyday life (e.g., a moving car, a lit light bulb).
Instructional Materials
- Textbook (Basic Science and Technology for Primary School Book 3)
- Visual aids (charts showing energy forms and conversion examples)
- A small fan, light bulb, and electric stove for demonstration
- Flashcards with pictures of energy forms and devices
Reference Materials
- Ijiyemi, C. (2016). Foundations of Sci. & Tech for Primary School Book 3. Metropolitan Publishers, Lagos.
- Oyinlola, M., Rahaman, B., & Ezeume, I. (2015). Basic Science and Technology for Primary School Book 3 (Bec Edition). Spectrum Book Limited, Lagos.
Content
Properties of Energy
Energy Cannot Be Created or Destroyed, Energy Can Be Converted
1. Energy Cannot Be Created or Destroyed
Energy is never lost or destroyed. It can only change from one form to another. For example, when you eat food, the energy in the food doesn’t disappear; it changes into energy your body can use to play, think, or grow. This rule is called the law of conservation of energy. So, if energy is used up or seems to disappear, it has just changed into a different form!
Example:
- When you turn on a light, the electrical energy in the wires is changed into light and heat energy. The energy is still there, just in a different form.
2. Energy Can Be Converted (Changed)
Energy can be converted (changed) from one form to another. For example, in a car, chemical energy from the fuel is changed into mechanical energy that makes the car move. In a fan, electrical energy is turned into mechanical energy that makes the blades spin and create wind.
Examples of Energy Conversion:
- From Electrical Energy to Heat Energy: When you plug in a toaster, electrical energy changes into heat energy to make your bread brown.
- From Chemical Energy to Mechanical Energy: In a bicycle, the energy from your muscles (chemical energy) helps move the bicycle forward (mechanical energy).
- From Electrical Energy to Light Energy: A lightbulb changes electrical energy into light energy to brighten up a room.
Lesson Presentation
Step 1: Introduction
Begin by asking pupils: “What happens when you switch on a light at home? What do you think happens to the electricity when the light is on?” Engage the class in a brief discussion about how energy changes form.
Step 2: Explanation
Introduce the law of conservation of energy. Explain that energy cannot be created or destroyed, only converted. Use simple examples, like food providing energy for the body, or a moving car turning electrical energy into heat energy. Show a chart or diagram illustrating energy conversion.
Step 3: Demonstration
Use a light bulb and a small fan as an example. Plug in the fan and explain that electrical energy is converted to mechanical energy (the spinning fan). When you turn on the light, explain that electrical energy is converted to light energy.
Step 4: Guided Practice
Ask pupils to identify examples of energy conversions they see in the classroom or at home. Show a few devices like a toaster (electrical to heat) or a radio (electrical to sound).
Step 5: Independent Practice
Distribute flashcards with different appliances or energy forms on them. Ask pupils to match the cards that show energy conversion (e.g., fan and mechanical energy, light bulb and light energy).
Step 6: Feedback
Walk around the room while pupils are working. Provide feedback, clarifying any confusion. For example, if a student has trouble understanding how a car converts energy, explain that when a car moves, fuel energy is converted to mechanical energy, and when it stops, some of that energy turns into heat.
Evaluation
- Formative Assessment:
Ask questions during the lesson such as, “Can energy be destroyed?” and “What happens to the energy when you turn on a fan?” Use students’ responses to gauge their understanding. - Summative Assessment:
At the end of the lesson, give a short quiz where pupils have to match energy conversions (e.g., electrical energy to heat energy in a stove, mechanical energy to sound energy in a car horn).
Summary/Conclusion
Summarize the key points:
- Energy cannot be created or destroyed, only changed from one form to another.
- Energy conversion happens in many everyday devices (e.g., light bulbs, fans, cars).
- Understanding how energy changes helps us use it more efficiently.
Assignment
Ask pupils to write about one example of energy conversion that they have seen in their home or school. They should describe the type of energy being converted and the final form of energy.