Lemon Battery

1. Lemon Battery Materials: Lemon; zinc nail; copper strip/coin; multimeter/LED with multiple cells What you do: Insert two metals and measure voltage. What students see: A fruit produces measurable electrical voltage. Question: Is the lemon storing electricity like a normal battery? 2. Hand-Crank Generator Lights an LED Materials: Hand-crank generator; LED or small bulb What you do: Crank slowly, then faster; reverse direction if setup permits. What students see: Light brightness changes with cranking. Question: Where does the electrical energy come from? 3. Peltier Plate: One Side Hot, One Cold Materials: Peltier module; low-voltage supply; heat sink; temperature probes What you do: Power module briefly and compare both sides. What students see: One side cools while the other warms. Question: Where is the heat going?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Is the lemon storing electricity like a normal battery? Question: Where does the electrical energy come from? Question: Where is the heat going?