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What flames made of

  1. May 14, 2006 #1
    Can any tell what are fire flames made up of that we can see it.
     
  2. jcsd
  3. May 14, 2006 #2
    i just burnt a small pile of paper and what i saw was

    color and felt heat...

    the color appeared to be dependent of the intensity

    of the flame...

    a some points there appeared to be no color to the flame...

    it seemed to be only a distorted heat wave...like a mirage in the desert

    yet was too hot to put my hand in
     
  4. May 14, 2006 #3

    vanesch

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    I'd say that flames are essentially made of hot gasses, still in chemical reaction or not. There maybe some graphite or other particles in it too which emit radiation (black body radiation), and there may be some excited atoms/molecules and/or even ions around, which, through deexcitation, emit light or other radiation. But it is not a highly ionized plasma in any case (under atmospheric conditions).
     
  5. May 14, 2006 #4

    Hootenanny

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    I would agree with vanesch here, the characteristic colour is often given by the chemical which is buring, emitting radiation due to electron excitation. This is the basis of the flame tests used in chemistry (which analyse the emission spectrum). Elements have very specific colours sodium is yellow and copper is green for example.

    ~H
     
  6. May 14, 2006 #5

    rcgldr

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    When an element burns and gives off a specific color, is this a single frequency, or a combination of various frequencies? Also can flames produce (perceived) colors that don't exist in a rainbow or from a white light souce split up by a prism?
     
  7. May 14, 2006 #6

    Danger

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    Jeff, the colour won't be a 'single' frequency. It will, however, be restricted to a narrow range of frequencies. The principle is used not only in spectroanalysis, but also in the formulation of fireworks.
     
  8. May 15, 2006 #7
    Flames are hot glowing incandescent gas usually laden with burning particulates.

    If you smoke, try lighting your cigarette about six inches above the flame from your lighter or a candle. It works.
     
  9. May 19, 2006 #8
    could you explain "burning particulates" better? is it shining particles? particles emitting hot lights(energy waves)?

    that would be heat i think. it is the same thing when LUP focused light burns papers.

    I think of flames as groups of excited particles. The cause of excitation could be anything from chemical reaction (like the sun and firewoods) to overheat (like those happen when a short circuit occurs).
    Simply said, they are particles moving and emitting light.
    Note: Until now, i regard light more as particles than waves.
     
  10. Feb 6, 2010 #9
    I think "burning particulate" means a particle that hold a lot of energy relative to its mass.
     
  11. Feb 6, 2010 #10

    uart

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    Visible flames are a combination of both line spectra from the hot gases and combustion intermediaries (these often form the blue parts of the flame), as well as black body radiation from the larger particles, especially carbon soot and ash (which usually gives rise to most of the orange parts of the flame).
     
  12. Feb 10, 2010 #11
    Aren't flames the product of a chemical reaction which gives off heat and light and could be a synthesis or decomposition reaction
     
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