Bend a Candle Flame with a Magnet
Materials
 A
birthday-cake candle and matches
A
neodymium magnet at least 2 cm in diameter and 3 cm
long (1 inch diameter and 1.5 inches long) available
from Educational Innovations
NOTE: This activity will only work with a strong
neodymium magnet. Neodymium magnets are more than an
order of magnitude (10 times) stronger than common refrigerator
magnets.
Try This
Light the candle.
Bring one pole of the magnet near the flame. Notice
that the flame is deflected away from the magnet.
What's Going On?
Oxygen in the air is attracted to the magnet. But inside
the candle flame, the oxygen has been removed by the
very chemical reaction that made the flame glow. As
oxygen rushes toward the magnet, the oxygen-free flame
is forced to bend in the opposite direction.
Oxygen is paramagnetic—a material that
is slightly attracted to a magnet. (The attraction is
much less than for ferromagnetic materials such as iron,
which is why a very strong magnet is needed.)
So What?
If strong electromagnets can exert a force on a flame
equal to the force of gravity, then zero-gravity experiments
with flames could be conducted on earth. Scientists
need to understand combustion in zero gravity to design
better rocket motors and to ensure safety in a space
station during a fire.
Going Further
Place a piece of aluminum foil between the candle and
the magnet to shield the magnet from your view. Have
someone else randomly move the magnet toward and away
from the candle. See if you can tell when the magnet
is close to the candle.
This is what’s called a “blind” experiment.
It’s a technique scientists use to try to make
sure that they’re not imagining small results.
This activity was developed by Dr. Yoji
Takikawa.
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