Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why does Fire give off Smoke?

  1. May 14, 2006 #1
    I can why fire would give off gasses. In particular if one is burning CH4 there would be a lot of gaseous CO2 and H2O. Why, when I burn wood, does a fine particulate matter get kicked up into the air? Why does it not fall to the ground like ordinary solid matter? Is there a lot of frictional force between smoke particles and air, not unlike a feather?
  2. jcsd
  3. May 14, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    My guess would be that smoke (carbon particles) is being carried up by the hot air via convection.

  4. May 14, 2006 #3


    User Avatar
    Gold Member

    Hoot has it pretty much. Smoke isn't just carbon particles, but that forms the majority of most wood or paper smoke. Pretty much any particulate matter that survives the burning process becomes smoke. You can tell, for instance, the difference between burning wood and burning steak by smelling it. That's a result of the various chemicals involved.
  5. May 14, 2006 #4


    User Avatar

    and eventually the particles do fall to earth. (or maybe some particles end up in clouds seeding raindrops.)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook