A lemon can be used to demonstrate the conversion of chemical energy into electrical energy. To make a voltaic battery, gather a lemon and 2 inches each of paper clip and copper wire. In this experiment, the two different metals serve as the electrodes that allow the electric current to enter and leave the lemon battery. Gently roll the lemon on a table and then insert each piece of metal. The wires should be positioned in the lemon close to each other without touching. Touch the two metal tips with a moistened tongue. The small amount of voltage created by the lemon's liquid juices, wire electrodes and saliva will result in a slight tingle on the tongue.
With the supervision of an adult, children can create an electric light bulb using a small jar, a cork lid stopper, 3-feet of insulated copper wire, a 6-volt battery and thin iron wire, such as picture wire. Cut the copper wire in half and remove 1-inch of the plastic coating at each end. Insert each wire through the cork stopper and allow about 2 inches to hang into the jar. Attach the thin iron wire to each end of the copper wire in the jar. Hook the opposite ends of the copper wire to the battery. When the connections are complete, the thin wire will glow -- similar to the filament in a light bulb.
Projects involving the concept of positive and negative charges can be easily demonstrated when magnetizing a screwdriver. Wrap insulated wire around a screwdriver and let the wire touch both terminals of a large, dry-cell battery. The result is a magnetized screwdriver charged with the voltage of the battery. Experiment to examine what types of material can be picked up and how long the screwdriver remains magnetized.
A super sparker creates very small lightening and requires material that maybe readily available in the home. Cut a small piece corner of a Styrofoam tray to resemble a small hockey stick. Using masking tape, secure the cut piece to the center of a tin pie plate and form a handle. Rub the Styrofoam tray on your hair and place it upside down on the floor. Grab the pie plate by the handle and drop it onto the tray. Touch the edge of the pie tray with the tip of your finger to create a spark caused by the static electricity. To get another spark, lift the plate by the handle and touch the tin with your finger. This process can be repeated over and over again, or performed in the dark.