For this project, you need a jar, a shallow plate and a lit candle. Place the candle in the center of the plate, lighting it once it's stabilized. Place the empty jar over the candle, making sure the bottom of the jar forms a natural seal with the plate. Because oxygen is needed for every burning process, the flame will go out because the oxygen is used up inside the jar.
This experiment requires a tea-light candle, a round container such as a salt shaker and matches or a lighter. Light the candle, then place it behind the container. Blow air toward the container. The candle will be blown out even with the obstacle in front of it because, according to Kids Science Experiments.com, "air flow follows the contour of the round container." The air meets up, joining together, and results in blowing out the candle.
This science project is like the candle in a jar project, except there's an added ingredient of water. Place a tea-light candle on a shallow plate, pouring a small amount of water around the base. Light the candle and cover it with the empty jar. Students will notice that when the flame goes out, the water rises in order to make up for the space created inside the jar when the oxygen is burned up.
This experiment requires that one candle be completely frozen and another, the control, should remain at room temperature. Light both candles in the same space to ensure the variables are the same, making sure both candles are identical except for temperature. Record notes on which candle burns faster. The frozen candle will burn at a slower rate because the cold wax requires more energy from the flame for melting the wax.