Introduction

In this hands-on activity, students will visualize how a battery works by modeling the flow of electrons through a simple circuit. Using labeled cut-outs, students will assemble and explain the function of key components – anode, cathode, electrolyte, and LED bulb – while reinforcing concepts of energy transfer and electric current. 

Student Objectives

Students will be able to

• Identify and describe the roles of the anode, cathode, electrolyte, and LED bulb in a simple battery circuit. 
• Model the direction of electron flow in a battery-powered circuit using labeled cut-outs and symbols.
• Explain how energy is transferred from chemical energy in a battery to electrical energy that powers a device.
• Predict and explain what happens when the components of a circuit, such as the LED bulb, are connected incorrectly.

Materials (per student group)

• Student Handout
• Modeling a Battery-Powered Circuit Student Handout
• Printed, cut out Component Cards (laminated for reuse if desired)
  • Anode (Zinc)
  • Cathode (Copper)
  • Electrolyte
  • LED bulb
  • 8-10 electrons
  • Arrows
• Printed Diagram Sheet
• (Optional) Tape or glue for anchoring

Procedure:

1. Print and prepare one full set of Component Cards for each student group.
2. Introduce the concept of batteries and how they work by watching the Introduction to Energy Storage video. Use additional visuals or a real battery if available.
3. Distribute the Student Handout, Component Cards, and Diagram Sheet to each student group. 
4. As students follow the instructions on the Student Handout, guide the activity and give students help when needed. Encourage students to talk through their thinking as they arrange their components. Let students try to figure the diagram out for themselves instead of solving it for them.
5. Once students have made their choices, have students show their diagram to another group and discuss differences, similarities or changes they want to make. Then, as a whole group, show students how to build the diagram correctly (this time, students can tape or glue their components down, if desired) and discuss the reasoning for the placement of each component.
6. Students will then consolidate their understanding by completing the Reflection Questions on the Student Handout.

Key Points

• Electron Flow Direction: Electrons should be shown moving from the anode to the cathode, passing through the LED bulb in the process. 
• Function of Each Component: 
  • Anode: Loses electrons (oxidation), starts the flow. 
  • Cathode: Gains electrons (reduction), completes the circuit. 
  • Electrolyte: Between the anode and cathode; allows internal movement of ions to maintain charge balance (not part of external electron flow). 
  • LED Bulb: Lights up when electrons flow through it in the correct direction. 
• Why the LED light works in one direction only: LEDs are diodes. They only allow current to flow one way. If placed backwards, the bulb won’t light up.

Answer Key

The Student Guide contains the Modeling a Circuit – Student questions.
Reflection Questions Answer Key:
Question 1: At the anode, electrons are lost in a process called oxidization. This is important because it gets the electrons moving to begin the flow into the wire.
Question 2: At the cathode, electrons are gained in a process called reduction. This is important because if the electrons had nowhere to go, the circuit would not be complete, and electricity could not flow. 
Question 3: The electrons help move the ions inside the battery and keep the chemical reaction going, so that the electrons keep flowing. 
Question 4: The battery stores chemical energy. When the electrons move, it turns into electrical energy. When the electrons go through the LED, that energy turns into light energy that we can see. 
Question 5: LED bulbs only let electricity flow in one direction. The positive side needs to be connected to the wire leading to the cathode, and the negative side needs to be connected to the wire from the anode. If the LED is placed backward, it will not light up, because the electrons could not flow through. 
Question 6: Answers will vary.

Diagram Activity Answer Key

Component Cards

Optional Extension: Energy Transformation Cards

Instructions
To reinforce the concept of where and how energy changes in the system, have students place the energy cards next to the correct components. 

Chemical energy ➞ Battery
Electrical energy ➞ Wires
Light energy ➞ LED bulb

Diagram Sheet