Methane is a delightful little molecule.
Every rotation, we discuss density for a few days. We might take
readings, solve problems, play with cartesian divers, have a discussion,
do some bookwork, and make a styrofoam/clay submarine... BUT the
thing that really gets the kids excited is methane bubbles.
The real point is to show that the methane
is less dense than the air in the room. I figure there's no reason
to let methane hang around, so why not ignite it.
If you let the bubble get to the ceiling
before ignition, you get a cool ring. When the ring sprawls out over
the demo mirror, you get a nice condensation of water that all can see.
Students are often surprised that combustion produces water!
