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This Week's Experiment - Oxygen, yes!
Greetings from Fort Pierce, Florida. I am here for a day of shows at Florida
Power and Light's Energy Encounter. Then I drive back north so I can fly to
Buffalo. Over the past few days I have rebuilt my million volt Tesla coil, to
make it even easier for me to travel by plane. I seem to be spending more and
more time flying and every time I find one or more ways to make the gear
smaller and lighter.
A few weeks ago, we looked at a classic experiment of putting a lit candle
under a glass. We saw that water was drawn into the glass, not by the oxygen
being burned up, but by the cooling of the air in the glass after the candle
went out. This week's experiment will allow us to do what many people thought
the first experiment was doing.
You will need:
a pie pan
water
a clear glass or jar
steel wool
vinegar
tape
Carefully fit a wad of steel wool into the bottom of the glass. If it does
not fit tightly, then use some tape to hold it in place. Pour a little
vinegar into the glass, to wet the steel wool. Pour off any excess vinegar.
Pour about two inches of water into the pan. Place the glass upside down in
the pan of water. The jar will be full of air, with the steel wool at the top.
Let the jar sit in the pan over night. You may want to look at it
periodically to see what happens to the water level, but do not move it until
the next day.
What happened? You should find that the water has risen into the glass. You
should also find that the steel wool has rusted. The two things are
connected. When iron or steel rust, they combine with oxygen to form iron
oxide (rust). As the steel wool rusted, it took the oxygen out of the air.
This lowered the air pressure in the glass, allowing the outside air pressure
to push water into the glass to balance the pressure. When the rusting steel
wool has removed all of the oxygen from the air in the glass, the water should
have risen 1/5 of the way up the glass, as oxygen makes up about 1/5 of the
air around us. Almost all of the rest of the air is made up of a gas called
nitrogen.
When iron rusts, it gets heavier, as the iron is bonding with the oxygen in
the air. When iron filings are burned, they also get heavier, for the same
reason. This was one of the first proofs of the existence of the gas oxygen.
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Upcoming On-the-road schedule
April 19 - FP&L Energy Encounter, Ft. Pierce, FL
April 21 - 25 - Buffalo Museum of Science, Buffalo, NY
April 28-29 - School shows in Madison, Alabama
April 30 - Solar Energy Center, Cocoa, FL
May 1 - Nature hikes at Guana Refuge, Ponte Vedra, FL
May 4 - Berryhill School, Milton, FL
May 5 - Science Day, Grace School, Ocala, FL
May 7 - Yulee School, Jacksonville, FL
May 9 - Astronomy Day, Museum of Science and History, Jacksonville, FL
May 11-15 - School shows for FP&L, Ft. Pierce and Stewart, FL
May 16 - Scout extravaganza - NAS, Jacksonville, FL
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Each week I will e-mail you a new experiment that you can try yourself. I
look for experiments that are unusual, safe, dramatic, cheap, and fun. Since
this list includes teachers, parents, science buffs, and students, I will try
to give you a wide variety of things to try.
Please forward this e-mail to anyone that you think might enjoy it. If you
received this e-mail from someone else and would like to be on the list, just
send me an e-mail at krampf@aol.com, asking to be added to the Experiment of
the Week List. If you ever want off the list, just send me an e-mail requesting
to be removed.
Check out our web site at:
http://members.aol.com/krampf/home.html
for information on:
Watt is Electricity, the million volt electric show
The Nuts and Bolts of Lightning
Burning Questions, the science of fire safety
Educational consulting
Educator workshops
From Robert Krampf's Science Education Company
4850 A1A South
St. Augustine, FL 32084
(904) 471-4578