Candle chemistry

Experiment with the chemistry of candles and make a flame jump through the air.

Aims

Make a blown out candle relight as if by magic.

ExpeRiment to find out how long a candle will burn in different amounts of air.

Learn about the chemistry of how a candle burns.

  • Media

    At least one tea light or other small candle.
    Gas-powered cooker lighter (or long handled matches).
    Glass jars or glasses of various sizes.
    Stopwatch (maybe the one on your smartphone) or other way of measuring time.

About this activity

Lisa and Josh make a candle relight as if by magic. They investigate how long it takes for a covered candle to go out, and find out why a candle can keep burning for a longer time in a larger jar than in a small one.

In this fun, free science experiment to do at home with young children, Lisa shows Josh how to relight a candle without touching the wick. When a candle is blown out, the wick stays hot, and wax continues to be drawn up through it before evaporating. This wax gas above the candle can be relit, meaning that a flame will appear to jump from Lisa’s lighter to the candle wick.

Josh times how long it takes for candles to go out when covered by different sized jars. A candle flame is the result of a chemical reaction between wax gas and oxygen in the air. When you trap the candle in a jar, it only has a limited amount of oxygen. Josh finds out that in larger jars, there’s more oxygen so the candle can keep burning for longer, but that the flame will eventually go out.

Download the information sheet for more ideas, and the badges and certificates for afterwards! Share photos and videos of your experiments on our Facebook page.

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