Candle chemistry

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

a young boy and his mother sitting at a table with a teacandle in the middle
Recreating one of Michael Faraday's candle experiments, Image credit: The Royal Institution


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.

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.