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| Q: | I was wondering if there is a fuel out there that is good for starting fires with one that creates a blue flame
-Faye (age 13) |
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| A: | Hi Faye --
The color of a flame depends on the material being burned. There
are lots of fuels that will produce blue flames when burned; the most
commonly available one in the household is natural gas. You can look at
the flame on the stovetop (if your stove uses natural gas) or furnace
to see a pretty blue flame (don’t get too close! These are hot!).
Natural gas, or any other pure hydrocarbon such as butane or propane
will burn a light blue.
Many ordinary flames (for example, burning wood or paper or
candles) are yellow because of the presence of a small amount of sodium
atoms in the fuel. Sodium atoms glow yellow very brightly when they are
heated; yellow light is their very favorite color to emit (this
particular shade of yellow is called the "sodium D line" because of the
electron orbits involved in the sodium atoms before and after the light
is emitted). Sodium street lights are very very yellow for the same
reason.
Other chemicals make flames burn other colors. Here is a nifty web
site listing what is added to commercial fireworks to make them glow
all the different colors:
http://chemistry.about.com/library/weekly/aa062701a.htm
This site lists copper compounds as good sources of blue (in case the site goes away someday, here is the "blue list"):
copper compounds + chlorine producer
copper acetoarsenite (Paris Green),
Cu3As2O3Cu(C2H3O2)2 = blue
copper (I) chloride, CuCl = turquoise blue
The color of a fire won’t depend on what you use to start it, however, just what is burning at the time.
Tom
(republished on 07/24/06) |
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