Things You Will Need
- D-cell battery
- Aluminum foil
- Two pennies
- Steel wool, not soap-filled (available in hardware stores)
- Two paper clips (plain metal)
- Masking tape
- Small thumbtack
- Cut a piece of aluminum foil, 24 inches by 12 inches.
- Fold the aluminum piece in half lengthwise five times to form a thin, 24-inch-long strip.
- Cut the aluminum strip in half to form two 12-inch strips.
- Clean the pennies by rubbing them with steel wool.
- Tape one end of each of the aluminum strips to the ends of a D-cell battery.
- Wrap the free ends of the aluminum strips around a penny so that about one-half of each penny is left exposed. Secure the aluminum strip to each penny with a paper clip.
- Have an adult cut a potato in half.
- Push the exposed edge of the pennies about 1/2-inch apart into the sliced end of the potato.
- Mark the side of the potato attached to the positive end of the battery with a thumbtack. The positive end of the battery will be marked with a plus sign.
- Wait about one hour, then remove the pennies from the potato.
What Should Have Happened
The penny connected to the positive end of the battery created a green substance on the potato. The positively charged copper particles in the penny combine with negatively charged particles in the potato to form a green copper compound.
Webdate: June 11, 2002
Updated: July 2004
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