This experiment shows how a battery works using electrochemistry. The electrons inside the copper are going to react with the acid in the lemon juice to make a flow of current you can detect with a digital multimeter.
The copper electrons are chemically reacting with the lemon juice, which is a weak acid, to form copper ions (cathode, or positive electrode) and bubbles of hydrogen.These copper ions interact with the zinc electrode (negative electrode, or anode) to form zinc ions. The difference in electrical charge (potential) on these two strips causes a voltage. You need two different metals in this experiment that are close, but not touching inside the solution. If the two metals are the same, the chemical reaction doesn’t start and no ions flow and no voltage is generated -nothing happens.
