- 2 – Pennies
- Digital Clock with Wire Attachments
- 2 – Galvanized Nails
- 3 – 8” insulated copper wire (make sure 2” of the insulation is stripped off of one end)
- Cut the potato in half and put the flat ends facing down onto the plate.
- Take one wire and wrap the exposed wire around one of the galvanized nails.
- Take another wire and wrap the exposed wire around one of the pennies.
- Stick the nail and penny you just used into one half of the potato. (MAKE SURE THEY DON’T TOUCH!)
- Wrap the 3rd wire around the 2nd penny, and place it into the other half of the potato.
- Place the 2nd nail into the other half of the potato as well. (DON’T WRAP IT WITH WIRE)
- Take the wire that is attached to the penny from the 1st potato half and connect it to the nail in the 2nd potato half.
- Take the free wires and connect them to the wires on the digital clock.
Does the Clock turn on? If it doesn’t, rearrange the wires connecting the clock differently.
LOOKING DEEPER INTO POTATO CLOCKS
There is a chemical reaction that causes electrons inside the potato ‘battery’ to start moving. The chemical reaction is called “Redox Reaction”. The nail from one potato causes the positive part of the circuit. The phosphoric acid in the potato reacts with the zinc in the nail, which in turn, releases electrons. The Zinc loses electrons and the copper wire releases hydrogen ions because of the reaction with the phosphoric acid. The ions gain the electrons. Whatever gains the electrons is the negative part of the circuit! Amazing, right?!