Combustible oils can be found in many everyday 'feedstocks.' Here's an easy demonstration that's somewhat safer than the so called greasebombs I saw in Hidden Valley last weekend:
Materials- tea candle, lighter, whole orange or grapefruit
Time- about 5 minutes
Light the tea candle. Peel part of the orange or grapefruit (this is a good chance to talk about energy passing through the food web). With the white side of the peel toward you and the orange side of the peel toward the candle, squeeze the peel and watch the fireworks. If it doesn't work the first time, try a fresher piece of fruit.
Discussion- Does it work with other fruits? What other plants might contain similar oils? If you spray svo at the flame, this experiment doesn't work. Why not?
