To do this experiment, you will need a small votive candle, a saucer and a glass jar. Put a little water in the saucer and place the candle on the saucer. Light the candle and let it burn for a few seconds. Place the jar over the candle. As the oxygen runs out, the flame will extinguish. This can be used as a great science fair project for elementary school students. Take pictures to show the candle before it is lit, while it is burning, with the jar over the flame and the flame extinguished.
For this project you will need a glass jar, a small candle that can stand alone, baking soda and vinegar. Put some baking soda around the bottom of the candle. Don't get it on the wick. Light the candle and then pour a couple of tablespoons of vinegar around the sides of the jar. Avoid getting the vinegar on the flame. Have children record what happens when the vinegar reacts with the baking soda to deplete oxygen. This experiment simulates how a fire extinguisher works to put out a fire. Pictures can be taken of the process and used as a science fair project.
A fireplace or a grill is needed for this experiment. Take small pieces of wood and make two stacks. With one stack, stack the wood close together directly on the bottom of the surface you are using. With the second stack of wood, stack the wood loosely on a grate or some type of raised surface. You can use small rocks to stack the wood on if a grate is not available. When both stacks of wood are lit, the stack that is arranged loosely will burn better than the other stack because the wood is raised and has plenty of room to allow oxygen to flow through.
Do an experiment several times when you are using it as a science fair project. Take pictures each time you do the experiment so that you will have many photos to choose from for your project. Read books or articles about a fire's need for oxygen, so that you will be able to write a hypothesis and show knowledge of your project. With all of these projects be sure that an adult is present to help students with the lighting process.