Is fire a plasma

[phreakstep]

So is fire a form of plasma?

I know a lot of you people will say it isn't because it is not hot enough however the temperature of fire is depended on 2 things:

- Fuel

- Oxygen

So if you start a camp fire well that is not plasma but if lets say find a fuel that burns with the help of air burns at 10000 celsius (it is hypothetical question) that I think would be enough temperature to start ionizing the gases so in that sense it would be plasma.

So is fire a plasma in general? or it is something like plasma and not plasma at the same time lol?

[sepulchrave]

I assume you are talking about the flame.

A flame is a combination of gas and solids (small particles of ash and soot). The colour comes from general black-body radiation (thermal) and electronic transitions (decay of excited electrons).

As you point out, if you get a fire hot enough it will indeed form plasma. A plasma is an ionized gas, and a conventional fire heats the gas/soot/ash enough to excite the electrons, but not fully eject them.

I think it is instructive in this situation to think of a plasma as a special form of gas, rather than a conventional flame as a sort of `pre-plasma'. The really interesting parts of plasma are its electric and magnetic properties, neither of which are really manifest even if the fire is hot enough to ionize the gas.

[Admiral Danger]

i was thinking about this the other week, i couldnt really come to a conclusion so i just accepted it as a gas since its what the schools have been telling us it is.

[sinewave]

I assume you are talking about the flame.

A flame is a combination of gas and solids (small particles of ash and soot). The colour comes from general black-body radiation (thermal) and electronic transitions (decay of excited electrons).

As you point out, if you get a fire hot enough it will indeed form plasma. A plasma is an ionized gas, and a conventional fire heats the gas/soot/ash enough to excite the electrons, but not fully eject them.

I think it is instructive in this situation to think of a plasma as a special form of gas, rather than a conventional flame as a sort of `pre-plasma'. The really interesting parts of plasma are its electric and magnetic properties, neither of which are really manifest even if the fire is hot enough to ionize the gas.

Right, plasmas are defined by ionization which is driven by high energy electrons.

[phreakstep]

I assume you are talking about the flame.

A flame is a combination of gas and solids (small particles of ash and soot). The colour comes from general black-body radiation (thermal) and electronic transitions (decay of excited electrons).

As you point out, if you get a fire hot enough it will indeed form plasma. A plasma is an ionized gas, and a conventional fire heats the gas/soot/ash enough to excite the electrons, but not fully eject them.

I think it is instructive in this situation to think of a plasma as a special form of gas, rather than a conventional flame as a sort of `pre-plasma'. The really interesting parts of plasma are its electric and magnetic properties, neither of which are really manifest even if the fire is hot enough to ionize the gas.

Thank you very much.

Yes I meant flame not fire itself lol.

[Brotherbandit]

The really interesting parts of plasma are its electric and magnetic properties, neither of which are really manifest even if the fire is hot enough to ionize the gas.

Well actually...

yeah, check out this video before you make a serious faux pas: [media=]

[/media]

i was thinking about this the other week, i couldnt really come to a conclusion so i just accepted it as a gas since its what the schools have been telling us it is.

After so many centuries, you would think that we'd learn about the dangers of accepting things without challenging them first.

Edited April 22, 2013 by Brotherbandit

[pallidin]

A "normal" fire can not, nor ever will, create a pure plasma event.

However, lightning can reach temperatures enough to create plasma, and often does.

It can also be done in a microwave oven(not recommended) under certain conditions.

[S2F]

It can also be done in a microwave oven(not recommended) under certain conditions.

I still want to try it, I just need to get my hands on a crummy but still working microwave with enough power to do the trick. I could use the one in the kitchen but the wife would club me over the head with it if she found out.

[pallidin]

I still want to try it, I just need to get my hands on a crummy but still working microwave with enough power to do the trick. I could use the one in the kitchen but the wife would club me over the head with it if she found out.

Be VERY careful if you do.

Explosion, though not often, can result.

Please take the time to read all literature on microwave plasma creation, for your safety.

[Brotherbandit]

Would you say that a flame is a solution of plasma and gas?

[sepulchrave]

Would you say that a flame is a solution of plasma and gas?

I wouldn't, but I also disagree with the (admittedly, very cool) video you posted above. (For example, the video didn't demonstrate that fire produces free ions and electrons in any substantial quantity, only that fire + 20 000 volts will produce significant charge separation. Franky, 20 000 volts alone will produce significant charge separation in a lot of things, you just won't be able to see it.)

In my opinion an exothermic reaction that creates some amount of charge separation and increases local conductivity is not necessarily a plasma, any more than the air near the surface of a metal exposed to ultraviolet light is a plasma.

In fact, I am reluctant to describe transient chemical reactions as being any specific ``phase of matter''.

But, this is just an opinion. Flames clearly do exhibit similar properties to gases and plasmas, so I wouldn't say it is wrong to consider flame a mixture of gas and plasma.

[S2F]

Be VERY careful if you do.

Explosion, though not often, can result.

Please take the time to read all literature on microwave plasma creation, for your safety.

Oh, no doubt, I'm not that stupid. Indeed, I would advise caution as well as safety precautions for anybody thinking about trying it.