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  • What is a candle flame really made of?

  • I am at the Palace of Discovery in Paris to do an experiment

  • that beautifully demonstrates the answers.

  • Ok so we're turning on an electric field here

  • and we see that the flame is spreading out.

  • Thats very cute,

  • it's like a butterfly.

  • And you can see that the flame

  • has two separate pieces to it now.

  • One is going towards the negative plate.

  • Those would be the positive ions,

  • and the negative ions will be going towards a positively charged plate.

  • So we see the flame kinda flattening out.

  • But if that didn't convince you

  • that flame contains ions,

  • then check part two of our experiment

  • where we compare the conductivity of a

  • flame to the connectivity of air,

  • which is normally a pretty good insulator.

  • It requires about 10,000 volts

  • to break down a centimeter of air.

  • So right now this plate is is about 20,000 V.

  • You see that the spark is only little,

  • but if I put it around the flame,

  • we will see if we can get a bigger spark happen.

  • Look at that, yeaaa!

  • Because the flame has those ions in it,

  • that means that we can break down

  • a greater distance of air.

  • This greater conductivity.

  • It's awesome! You love doing this, right?

  • A strong enough electric field

  • can actually extinguish the flame

  • but watch carefully what happens when the flame goes out.

  • Just like in the flame, the opposite charges in the smoke

  • are pulled in opposite directions.

  • Now while some may argue that a flame is not

  • truly a plasma because it's not hot enough

  • and it doesn't have a high enough density of ions,

  • one thing is for sure, it does contain ions

  • which have important electrical properties,

  • which can be demonstrated if you have a strong enough electric field.

What is a candle flame really made of?

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