Werklund School of Education

University of Calgary | Undergraduate Programs in Education

Lesson Overview

Dates March 2025 Subject Science / STEM
Grade Level Grade 2 Length 60 Minutes
Unit Energy Exploration Lesson # 8
Teacher Lucas Johnson

Identify Desired Results

Learner Outcomes

  • Understand basic principles of chemical batteries and energy conversion.
  • Construct a simple circuit using a battery, conductors, and a load.
  • Observe energy transformation from chemical to electrical to light.

Objective (Student-Friendly)

  • I Know: Batteries store energy in chemicals.
  • I Understand: A circuit is a circle path for electricity.
  • I Can: Build a battery out of a lemon to light up a bulb.

Assessment Strategies

Formative:

  • Observe group assembly: Are the connections secure and path complete?
  • Ask: "What part of the lemon helps the electricity move?" (The juice/acid).
  • Check circuit diagrams for correct labeling of source, path, and load.

Differentiated Learning & Resources

Resources

  • Lemons & Pennies (Copper)
  • Galvanized nails (Zinc)
  • Alligator clip wires
  • Low-voltage LEDs

Personalization

  • Challenge: Test other fruits (apples, potatoes) to compare power.
  • Support: Pre-insert metals into lemons for students with motor difficulties.
  • Safety: "Wash hands after handling the juice and metal!"

Lesson Sequence

1. Hook: Lemon Power? (2 min)

  • Hold up a standard AA battery and a lemon. Ask: "This battery has energy inside. Do you think this lemon does too?"

2. Explicit Instruction (10 min)

  • Chemical Energy: Energy stored in substances, waiting to be released.
  • Electrolyte: The juice (acid) that helps electricity move.
  • Electrodes: Two different metals (Copper and Zinc) that react with the acid.
  • Conversion: Chemical (Lemon) -> Electrical (Wires) -> Light (LED).

3. Activity: The Lemon Battery (30 min)

  • Step 1: Insert the copper penny and zinc nail into the lemon.
  • Step 2: Connect the alligator clips to the penny and nail.
  • Step 3: Connect the other ends to the LED legs.
  • Troubleshooting: "If it doesn't light, try flipping the LED! It only works one way."

4. Wrap-up and Reflection (15 min)

  • Discussion: "What happened when the metals touched the juice?" (Chemical reaction).
  • Journal: "Draw your lemon circuit and color the glowing light."

Glossary

  • Chemical Energy: Energy stored in stuff like batteries or food.
  • Circuit: A complete circle path for electricity.
  • Conductor: Something that lets electricity travel (like metal).
  • Load: The part that uses the energy (like the light bulb).