| Laboratory Lab Safety Rules Lab Tools Simulations Experiments |
Making
Invisible Ink
The
easiest way to perform this trick is to use lemon juice
(your sweat would also work). Using some kind of writing
tool, apply lemon juice onto a plain piece of paper. Make
sure you let the paper air dry. Then, hold the paper under
a heat source (candle, iron, just be careful not to light
the paper), and the message you wrote should turn up.
Here
is a more complicated alternative. Mix about 1 tsp (5 ml)
cornstarch to 1/4 cup (60 ml) of water. Cook it a bit (you
can nuke it in the microwave for a minute, stirring once).
Let it cool, and write your message. Once dry, sponge it
with a solution of iodine (toxic!) and water (10 or so drops
in 1/4 cup (60 ml) of water). Your writing will appear in
a dark blue, and the paper will be a lighter blue. If you
substitute lemon juice for the cornstarch solution, you
will end up with white text on a light blue background.
If you are artistically minded, you should be able to get
some interesting effects using this information.
Volcano:
potentially dangerous method
This
involves burning chemicals, and is therefore dangerous.
Take all necessary precautions. Also, the chemical used,
ammonium dichromate, is quite toxic, so keep it awy from
the kiddies! It is also a possible cancer-causing agent
(like most things on our planet seem to be), so the project
should not be done often. The fumes should not be breathed.
Do this outside! T he volcano must be fireproof (no papier-mache)
and the bottle must be substituted with a shallow can (small
cat food or tuna cans work well). Once everything is dry
and ready to go, place 10-15 wooden match heads in the can.
Fill the can with ammonium dichromate. Drop a lit match
inside. Keep your hands away, as it will flare up, spark,
sputter, and send a green lava flow spilling over the sides.
This thing will get hot as heck, as will the lava, so be
very careful not to get burned.
Fake
glass
Using
sugar, a fake sheet of glass similar to the type used for
prop bottles in movies can be made. This is the sort of "glass"
that is often seen breaking in fight scenes in cowboy films.
The finished product is translucent and brown. Butter a baking
sheet and put it into the refrigerator to chill. Pour a cup
(250ml) of sugar into a small pan over a burner set to low.
Stir constantly until the sugar melts. It will seem to take
forever but eventually it will turn brown and melt. Keep stirring
until it has melted completely. When it has melted, pour it
onto the baking sheet, which should be cold and as level as
you can get it. Let cool. To clean the pan, fill it with water
and boil. This will dissolve the sugar clinging to the sides.
This
above experiments are contributed by http://freeweb.pdq.net/headstrong/default.htm
© 1998-2000 Brian Carusella All rights reserved.
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