Explore the concept of electron flow with a hands on circuit demonstration.

- Grade 9
- Thought Starter
- 20 mins

Your students *become* the circuit in this active, energetic demonstration that has them passing “electrons” to each other.

- 40 to 50 balls (or bean bags) in a bucket
- A large space

Get your students on their feet and in a large circle, with an arm’s length between them. While this activity seems simple, it will test the concentration skills of your students as they work to pass and receive balls at the same time. The rule here is that each student should have one ball, and only one ball, in their possession at any moment.

In this activity, the balls represent electrons that flow through a wire, represented by the students.

- Choose one person in the circle to be the light bulb, also known as the load.
- Give each other student one ball.
- Choose a location in the circle, between two students, to place the bucket. This represents the source of electricity, like a dry cell (battery).
- Have the student to the left of the bucket say, “Pass”, at which point they will pass their ball to the right hand of the student to their left and will then pick up another ball from the bucket. All the other students, when they hear, “Pass,” will pass their ball to their left, and will receive a new ball from the person on their right.
- The student who is acting as the light bulb will say, “On,” while passing their ball to the left and receiving a new ball from the right.
- The student at the end of the circuit, who is to the right of the bucket, places their ball into the bucket, and receives a new ball from the right.
- Repeat the process as often as you’d like, removing balls from the bucket and passing them around the circle on the command, “Pass”. As long as the balls pass through the person who is the light bulb, it will remain on.

- After several passes, remove the bucket and call out, “Open circuit.” When you do this, there will be no bucket to take balls out of or return balls to, and because each student must have one ball in their possession, no balls can be passed around the circle.
- Instruct the student who is the light bulb to say, “Off.”

- Insert the bucket back into the circuit at a different position, and call out, “Closed.” That’s the signal for the students to begin handing balls around the circle again.

- Repeat the cycle as often as you want. Have different students take on the role of the “load” and talk about what objects other than light bulbs could be the load in your demonstration.
- Try passing the balls more quickly around the circle. This is equivalent to increasing the current in a circuit.
- Have students pass the balls with more force, and explain that this is analogous to increasing the voltage in a circuit.
- Gradually remove balls from the pail. When there are no more balls in the pail, the students should stop passing them so they can each have one ball in their possession. Encourage discussion around the idea that this is the same as a battery running out of power.

Gather the class and discuss the components of a circuit, and ask your students to identify those components in your demonstration. Encourage discussion around the fact that there are always electrons in conductive materials, but if the electrons aren’t moving, the light won’t go on.

- Note how your students participated in the demonstration and class discussion.
- Have your students write a brief reflection explaining how their demonstration represented modeled electron flow and the basic components of a circuit.

- Draw a circuit diagram on the board with symbols representing the components of a circuit:
- Source
- Load
- Switch
- Conductor

- Have your students use the diagram to talk about the roles they played in the activity.

An electric circuit provides a continuous path for electricity to flow through. There are three parts to an electric circuit:

- An energy source, like a dry cell or battery
- A load, like a light bulb or resistor
- Conducting material, like a wire

The energy source provides power to the circuit, while the load makes use of the energy available. The conductor connects the energy source to the load and provides a path for the electrons to flow.

A switch can also be included as a means to open and close the circuit, controlling the current. When an electric current enters a load it converts that electrical energy. A light bulb converts electricity into heat energy and light energy.

Circuit diagrams use a universal set of symbols, so can be understood anywhere in the world. The symbols also make it easier to draw complicated circuit diagrams showing different components.

- Voltage, current and resistance
- Circuits

- Demonstrate a sustained intellectual curiosity about a scientific topic or problem of personal interest

- Experience and interpret the local environment

- Express and reflect on a variety of experiences, perspectives, and worldviews of place

- Transfer and apply learning to new situations