What's In A Candle Flame?
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it as a quick demonstration that flames contain ions and conduct electricity, which comes up in questions about whether fire is plasma and why flames discharge charged objects.
Recommended by 0 people across 0 different months, 2012 to 2025.
What it is
A short Veritasium video that asks whether a candle flame is a plasma. It places a flame between two high-voltage metal plates, where the flame stretches and splits as positive and negative ions are pulled in opposite directions, and sparks travel through the flame more easily than through air.
What people said
Cites PotatoIn · 2012-11 · Physics Stack Exchange · on “Does Fire Conduct Electricity? Why?”
Recently, I have stumbled upon a YouTube video by Veritasium describing the conductivity of fire. My question is: how exactly does fire conduct electricity? I am a high school student; therefore appropriate language is expected. [this video]
Cites mehfoos · 2013-08 · Physics Stack Exchange · on “Is fire plasma?”
Firstly, 'Fire', according to numerous comments and answers [here][1] is a 'process', in which case, the answer to the question will be 'no', since plasma is a state of matter. It would be unfair to leave it there by blaming the semantics, and given the abundant references to 'flame' region, I am going to assume that that is what the question meant to ask. I am also assuming that proving a candle flame constitutes plasma is enough to sufficiently answer the question. From some papers (a quick google search gave me [2,3]) that flames have ionised content and that they are electrically conductive. My suspicion was that not all flames are conductive, but [3] includes the statement: It has been
Cites Farcher · 2017-05 · Physics Stack Exchange · on “Why does a charged insulator gets discharged when brought close to a candle?”
This is very common way of discharging apparatus when doing electrostatics demonstrations or experiments. The flame contains both positive and negative ions as shown in this video [this video] . So bring a flame close to a charged object has the ions of the opposite charge to the object attracted to the object and discharge it.
Cites Dario Seidl · 2025-04 · Physics Stack Exchange · on “Is fire plasma?”
In this Veritasium video [this video] , they demonstrate that a candle flame has ions by putting it between two charged plates. The flame splits into a positively charged and a negatively charged flame. Whether that means it's a plasma, they just say it depends on your definition of plasma: "Is a flame really a plasma? Well it depends on your definition of plasma, but there are certainly ions in a flame, formed as molecules collide with each other at high speed, sometimes knocking electrons off of their atoms."