Why does fire have different colors and shapes?

[MR]

What is fire? I learned once upon a time that it's plasma, but that doesn't really get me anywhere... why is it colored/shaped the way it is/etc etc etc?

thanx folks!

 

[ph_low]

I asked both my physics teachers this a few weeks back.
I think i remember one of them saying that it was excited electrons, but i forgot what the other one said

 

[ph_low]

about the colour, i think its related to the temperature of whatever is being set on fire, a higher temperature flame will be giving out more energy, therefore changing the colour of the flame.

 

[Integral]

Here are a few links to other threads about flame.
https://www.physicsforums.com/showthread.php?t=51098&highlight=flame
https://www.physicsforums.com/showthread.php?t=39910&highlight=flame
https://www.physicsforums.com/showthread.php?t=28250&highlight=flame


Fire is the result of a chemical reaction. This reaction releases energy in the form of heat, the released heat, vaporizes chemicals in the fuel, these vapors are composed of energetic molecules which form the flame. The colors in the flame are created as excited electrons cascade to more stable orbitals within the molecular and or atomic structure. Thus the color of the flame is dependent on the chemicals present in the fuel.

The color of the coals on the other hand is essentially black body radiation, the color is determined by the temperature of the fire.

 

[MR]

thanks, Integral!