Comparing the burning speed of scented and unscented candles
The hypothesis that unscented candles burn more quicky than scented ones is proven to be false. All the candles burned at almost the same rate.
Candles have been used as a source of light before electricity was discovered, and the light bulb invented. They are normally used in religious ceremonies. Scented candles are normally used in aromatherapy. Most birthday celebrations will not be complete without blowing the candles on a birthday cake. They are most useful as a light source during power failures that occur at night, although today, battery powered torches/lanterns are a preferred alternative.
The experiment can also be done to compare the burn rate of different colored candles.
Try to repeat the experiment to compare the weight of the candle instead of its height. Do you think there will be any difference in your findings?
Candle - http://en.wikipedia.org/wiki/Candle
Does scent affect how a candle burns? - http://candles.lovetoknow.com/Does_Scent_Affect_How_a_Candle_Burns
How does a candle work? - http://home.howstuffworks.com/question267.htm
Be careful when handling fire. Ensure that the experiment is conducted in a well-ventilated laboratory or in a safe location, with no flammable materials lying around. Adult assistance is required.