The Three-Part Candle Flame
You will need: Candle, piece of cardboard.
Light a candle and when the
flame is burning steadily study it carefully. It consists of three parts. In
the center is a bluish area which contains the unburned gases from the candle
wax. Surrounding this center area is the brightest part of the flame. This is
composed of burning particles of carbon which give most of the light from the
flame. Outside these two parts of the flame is a fainter area where the burning
of the gases is completed.
With care, you can produce
proof of these three parts of a candle flame. Cut a piece of white cardboard
and hold it steadily in a candle flame for 3 or 4 seconds (but not long enough
for the card to catch on fire). At the end of this time, lift the card quickly
away from the flame.
photograph on the right shows you the type of mark which the flame will leave
on the card if the experiment is performed carefully. The inside area of the
flame consisting of the unburned gases will leave the card unmarked. The
burning particles of carbon will leave a deposit of soot. And the outer area of
the flame will leave a fine scorch mark.