Attach the third piece of wire to the second battery and to the bulb. Place two bare ends of the wire into a beaker filled halfway with distilled water. Put the wire ends into the salt. Replace the sugar water with plain distilled water. Add the salt.
Ions conduct electricity.
Some ideas for natural events include lightning, solar and lunar eclipses, and rainbows. Make a miniature earth and its magnetic field by covering a bar magnet with some modeling clay, and then forming the clay into a sphere. Keeping the magnet upright, place the clay-earth model on a table. Cut a strip of cardboard to represent the equator, wrap it around the model, and tape the ends. Sprinkle iron powder or filings on the model.