"Lemon Battery" Return to list of pracs

Aim: This activity is used to contruct a lemon battery.

Equipment: The equipment includes...  

• two wires (with alligator clips?);
• One lemon;
• a piece of copper metal;
• a piece of zinc metal.

Method: Stick a piece of copper and a piece of zinc into a lemon about 3cm apart. Attach one wire to the zinc and the other wire to the copper. Touch the open ends to your tongue. What do you feel?

Background knowledge: Inside the lemon is citric acid. It acts as an electrolyte (a conducting liquid). When you touch your tongue onto the two wires you begin to conduct electricity through this electrolyte. The electricity comes about since one of the metals starts to collect electricity and the other loses it. As a result the copper begins to dissolve and the zinc begins to collect a metal coating on it. This is the whole process involved in any battery. It happens because of general chemical properties of metals react differently to each other.