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What is the composition of fire? Guillermo Davies Ore |
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Chris - Fire looks like a solid thing but it’s not. It’s actually just vapour. When you heat something up to a high temperature it shoves out chemicals which are volatile and flammable. They mix with oxygen which is coming from the air around them. They combust so they react with the oxygen and they burn releasing heat. They also produce some degradation products or burning products from combustion. When you make that it glows. It’s incandescent and it gives out light at different wavelengths and different chemicals make different coloured lights. That’s why flames have different colours. Sodium’s very common and that makes flames an orange colour. If you have incomplete combustion. If you have some sooty particles in the smoke or the vapour they’ll glow orange as well. This is why you then see this orange pattern. |
July 2008 |
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Guillermo Davies asked the Naked Scientists:
Is fire any kind of matter? If so, which state of matter is it in, plasma,
gas?
What do you think?
- Guillermo Davies - 27th Jul 08
Fire is more of a 'process' than a substance, I should say. The 'matter' in a fire is the fuel and the Oxygen (plus Nitrogen, etc, which play no real part). The oxidation process is very rapid (and exothermal) which raises the temperature and provides the activation energy to continue the process. A plasma consists of a mixture of ions which are separated by virtue of the average thermal energy (i.e. temperature) being greater than the potential energy of attraction between the ions. There may be some flames where this happens but I don't think the temperature is high enough in 'yer average' candle flame. Aren't the fuels and the oxides covalent compounds so the energy would only be available if they actually combined? Go on, BC - put me right. I promise not to get abusive! - lyner - 27th Jul 08
Technically a plasma is any ionised gas (subject to being shouted at by physicists) so a candle flame is a dilute plasma. A decent meter will let you demonstrate that a candle flame conducts electricity. Not many of the molecules get ionised, but some do. Anyway, describing fire as a process rather than a material sums it up rather well. - Bored chemist - 30th Jul 08
Why do you hate me so? You are always putting me right (gnaws knuckles and kicks the cat). I should have remembered the 'flame probe' for detecting high voltage potentials. - lyner - 31st Jul 08
Of course, I love you dearly. But my love of scientific truth tends to win out.
- Bored chemist - 31st Jul 08
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- lightarrow - 1st Aug 08
That's true - particularly around the outside.
- lyner - 1st Aug 08
Why are you fighting? Someone tell what actually is fire. Does it have mass? Can it be made to occupy fixed shape? Why does it flutter? Why is it pointed at top? If it is a reaction, what are the reactants and products? If it were a process, I believe it shouldn't have been such a physical thing which could be seen. If it is a matter, it should be within three states. And Mr. Plasma, I request you to clear your concept as Mr. Process did.
- Pramod Kandel - 31st Jan 10
Fire is the physical manifestation of an incorporeal reality or the spirit of Yahweh. That is the reason it can't be defined under matter as the other elements are and there has to be three (3) conditions in order to invoke fire. This is showing that the creator Yahweh is a 3-fold unity being the Father, The Word and Holy Spirit. At no point in time will you get Yahweh without the 3-fold unity just like there can't be fire without those 3 conditions present which are the fuel, oxygen and heat.
See the whole discussion | Make a comment- Anthony Williams \"Bocetti\" - 5th Mar 10
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