Eli5 How does a flame light a candle if it is touched to the smoke trail of a just blown out candle.

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Eli5 How does a flame light a candle if it is touched to the smoke trail of a just blown out candle.

In: Chemistry

That is because in a candle, it is not the wick that is actually burning. The wick only absorbs the melted wax through and up its length to be burned at the tip of the wick. The “smoke” off a candle is actually the vapor and unburned particles of wax. So if you light that small wisp of “smoke” it can carry that flame back to the wax in the wick, in much the same way that you can light a trail of gasoline by holding a match *ABOVE* (and without touching) a pool gasoline

The smoke trial still has unburnt wax that the flame vaporised whe candle was previously lit. Basically, when the wax burns, most of it reacts with oxygen to make mostly carbon dioxide and water vapour but some of the wax doesn’t get the chance to react and is essentially left hanging! Bringing another flame to the smoke trail will give that vaporised wax a second chance to react with oxygen and the flame will follow the vapour trail back to the candle.

The smoke might contain some of the vaporised wax still coming off the candle.

FYI the wax itself it what actually burns in a candle, its fuel, the wick does burn to an extent, but it’s merely a mechanism to pull up wax to a usable point to burn. It’s also an imperfect one, candles are essentially imperfect oil lamps. Oil lamps work almost exactly the same only the fuel starts out as a liquid and needs to be bottled, but the wicking is the same in principle.