Things You will Need:
*thin copper wire (no coating)
*2 big paper clips
*small digital LCD clock
1)Wires. Attach one paper clip to a wire and set it aside. Attach another wire to one of the pennies. Wrap it in several directions to make sure you get a good contact. Set this aside too. Attach another penny to a length of wire and connect a paper clip to the other end. When you are done, you should have three wires. One with a paper clip, one with a penny and one with a paper clip and a penny.
2)Lemons. Prep the lemons for the science project by rolling them on a table to get the juices flowing. Once you get them going, cut two slits in each lemon, about an inch apart.
3)link the two lemons together by inserting the wire with a paper clip and a penny into each lemon. Then in the lemon with a penny into each lemon. Then in the lemon with a penny, insert the paperclip and a penny into each lemon. Then in the lemon, insert the paperclip with the wire attached. In the other lemon, insert the penny with a wire attached. If you did it right, you will have a penny and a paperclip in each lemon and a free wire coming out of each lemon.
4)Connect the positive and negative posts of the clock to the free wires. If it does not start up in a few moments, you may have to switch your positive and negative. The clock is powered by two different chemical reactions caused by the copper in the pennies, the steal in the paper clips and the acid in the lemons.