Introduction:
The experiment shows how a common potato and two metals can generate enough electricity to make a small digital clock function.

Aim:
Can a potato produce enough electricity to make a digital clock function? Materials: -- Large raw potato

• Pennies
• 2 large galvanized nails
• 6 long wire ( 3 pieces)
• small digital clock
• multi meter

How to do the experiment!

1. Cut the potato in half and place them next to each other, flat face down on a plate
2. Connect one end of the white wire to one of the nails and then place the nail into one half of the potato.
3. Connect the other end of the white wire to the battery holder inside the digital clock.
4. Connect one of the pennies to one end of the black wire then put the penny into the same half of the potato as the nail with the connected to it.
5. Connect the other end of the black wire to the other penny and place the penny in the other half of the potato.
6. Connect the other penny to the red wire and then place the penny into the half of the potato with the nail with the black wire connected to it.
7. Connect the other end of the red wire to the battery holder into the digital clock.
8. Put the red meter wire into the 15V hole in the multi meter and the black meter wire into the DC hole in the multi meter
9. Then put the other end of the black meter wire on the nail with the white wire attached to it and the red meter wire on the penny on the other half of the potato to the nail with the white wire attached.
10. Then measured how much electricity the potato battery produces.

How the experiment works!

The potato contains phosphoric acid. This acid causes a chemical reaction to occur at each of the electrodes (galvanized nail and copper penny). The reaction at the copper electrode strips electrons from the copper and attaches them to the hydrogen ions in the phosphoric acid. This depletes the electrons on the copper electrode, which makes it "hungry" for more. This process creates hydrogen gas.

The galvanized nail provides the zinc needed for the other reaction. The phosphoric acid dissolves the zinc in the nail and liberates electrons from the zinc atoms. The liberated electrons stay on the electrode and the resulting zinc ions migrate into acidic juices of the potato. This results in an excess of electrons on the zinc electrode. If a wire is connected between the zinc nail and the copper penny, the electrons will flow.

This flow of the electrons is the electrical current that makes the digital clock function.TheoryMy theory is that the phosphoric acid in the common potato would react with the zinc on the galvanized nail and react with the copper on the pennies to produce enough electricity to make the digital clock work. If it does produce enough electricity to make the clock work. The potato battery would produce 1.5 volts, which is the same as any AA sized battery.

Results

The results on the experiment is that the phosphoric acid in the potato, the zinc on the galvanized nails, and the copper on the pennies did produce enough electricity to make the small digital clock function. According to the multi meter the potato battery produce 1.5 volts of electricity which is the same as an AA size battery.Conclusion
The experiment had showed how the phosphoric acid, the zinc and the copper. Can produce electricity. I had also tired the potato battery on a small motor and a light but it didn't produce enough electricity to make neither the motor nor the light to work.
But the potato battery did produce enough electricity to make the digital clock work. The battery produced 1.5 volts.
It was really amazing that a single potato could produce electricity and enough to make a clock work.
I have really learnt about phosphoric acid, zinc, copper and how a battery operates.

Scientific Question: Can a potato produce electricity?