Integrated Science — Force and Energy

Subtopic: Electrical Energy (Age: 12)

Learning goals:

• Know what electrical energy is and where it comes from.
• Understand simple electric circuits (battery, bulb, wires, switch).
• Learn about conductors, insulators, safety and saving electricity.

1. What is Electrical Energy?

Electrical energy is the energy from tiny particles called electrons that move through a material (usually a metal). When electrons flow, they can light bulbs, run motors, charge phones and do useful work.

2. Sources of Electrical Energy (Kenya examples)

• Hydroelectric power — from rivers and dams (e.g., power stations using river water).
• Geothermal power — from hot underground steam (Kenya has geothermal plants).
• Solar power — from sunlight using solar panels (common in homes and schools).
• Wind power — from moving air using wind turbines.
• Batteries — small stored electrical energy used in torches, radios, calculators.

3. Simple ideas: Voltage, Current and Circuit (easy words)

- Voltage (V): like the "push" that makes electrons move (think of it as water pressure).
- Current (I): the flow of electrons (like the flow of water in a pipe). Measured in amperes (A).
- Circuit: a complete path that allows electrons to flow. If the path is broken (open), the current stops.

4. Easy Circuit Diagram (series circuit - battery, bulb, switch)

5. Conductors and Insulators

- Conductors: materials that let electricity pass easily (e.g., copper, aluminium, water with salts).
- Insulators: materials that do not let electricity pass easily (e.g., rubber, plastic, dry wood).

6. Uses of Electrical Energy

• Lighting homes and streets.
• Running machines, refrigerators, fans and televisions.
• Charging phones and radios used for learning and communication.
• Pumping water at farms and homes (important in Kenya).

7. Safety Rules (very important)

• Never touch broken wires or sockets — tell an adult immediately.
• Keep water away from plugs and electric appliances.
• Use dry hands when plugging or unplugging devices.
• Avoid putting metal objects into sockets.

8. How electrical energy changes to other forms

Electrical energy can become light (bulb), heat (electric stove), mechanical energy (fan motor), or sound (speaker).

9. Simple classroom activity — Make a torch (safe, adult supervised)

1. Materials: 2 small wires with ends stripped, 1 small bulb (torch bulb), 1 battery (AA), tape.
2. Connect one wire from the battery's positive end to the bulb's metal side; tape in place.
3. Connect the second wire from the bulb's metal bottom to the battery's negative end; tape.
4. If connections are good, the bulb lights. Break one connection to stop the light.
5. Discuss why the bulb lights (complete path for electrons) and how to make the circuit safe.

10. Quick facts and simple math

- Units: Voltage (V), Current (A), Power (W).
- Easy power idea: Power (W) = Voltage (V) × Current (A). Example: a 6 V bulb using 0.2 A uses 6 × 0.2 = 1.2 W.

11. Check your understanding (short questions)

1. What is electrical energy in one sentence?
2. Name two sources of electricity used in Kenya.
3. Why must a circuit be complete for a bulb to light?
4. Give two examples of conductors and two of insulators.
5. Mention three safety rules around electricity.