by Dr. Kathleen A. Carrado, Argonne National Labs |
Please note: All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.
Mix about 5 drops of red food coloring in the vinegar to make the "lava" orange, and pour it into the volcano. Now drop in the 1 tbsp. of baking soda, sit back, and watch it foam and froth. What it happening chemically? The acetic acid (CH3COOH) is mixing with the sodium bicarbonate (NaHCO3 ) to make carbon dioxide gas (CO2 ), water (H2O), and sodium acetate (NaC2H3O2 ). For the older kids, this is a "double replacement" reaction. It's the CO2 that makes the solution foam.
A variation on the volcano is to actually build it out of
dirt, shaping moist dirt around an empty soda bottle
and filling the bottle with the vinegar and baking soda.
Or you can shape the clay around the bottle. Please
read a bit about volcanos now to learn how real ones
work. Look in an encyclopedia, ask a scientist, check
out a book from your library, or cruise the internet!
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Written by: Kathleen A. Carrado, Chair of the
Elementary Education Committee.
References: "Chemistry for Every Kid" by Janice
VanCleave (p. 76) and the La Jolla Country Day School
web page: www.ljcds.pvt.k12.ca.us/html/cyberchem.
Keep the hook in the coat hanger but
re-shape the triangle to make it into a
square. Stretch the panty hose over the wire
square and tie knots in the ends (tie it
around the hook); clip off the rest of the hose.
Tear the newspaper into strips and then into
tiny squares. Put the pieces into the blender
and add enough water to cover it. You can
add the dryer lint for extra texture. Have an
adult turn on the blender and watch while it
runs for about three minutes. Turn off the
blender, put the stopper in your sink, and
pour in the gray gunk. Add four or five
inches of water, add the glue, and mix it up
really well using your hands. Put the wire
square in the sink until it's flat on the bottom,
then life it out very, very slowly. Very slowly.
When it's all the way out, let the water drip
out for a whole minute. Hang your square in
a dry, warm place until it is completely dried
out. Any moisture will wreck your paper, so
be patient. Peel your paper off of the square
and cut it, write on it, draw on it, do whatever
paper-y thing you like.
Your paper is in fact better than real
paper because it's recycled paper! Every
ton of paper we recycle can save 13 to 20
harvestable trees. Recycling helps keep the
planet in balance, so keep it up!
References: "Beakman's World" internet
site at: www.spe.sony.com/Pictures/tv/
If there is any insulation on the ends of
the wire, have an adult strip it off. Untwist the
paper clip and twist the end of one of wires
around it. Squeeze and roll the lemon to
loosen the pulp inside. Make two small cuts
in the skin of the lemon an inch or so apart.
Insert the bare wire and the paper clip
through these cuts into the juicy part. The
two wires should be close but not touching.
Connect the free ends of the two wires to the
terminals of the meter.
Now watch the meter move! What's
happening here? Electrochemistry causes
the two different metals (the copper wire and
the iron clip) in the acid (lemon juice) to draw
electrons away from one wire towards the
other. They flow out fo the lemon through
one wire, go through the meter and then
enter the lemon by the other wire.
You can even try to make your own
galvanometer (an instrument designed to
detect electrical currents) if one isn't
available to you. You'll need a compass, 15
feet of bell wire (hardware store), and a
small rectangular cardboard tray. Place the
compass in the cardboard tray. Scrape off
1/2" of insulation from each end of the bell
wire. Starting 6" from one end, wind the wire
tightly around the box, circling it at least two
dozen times. Leave another 6" of wire free
on the other end of the tray. Rest your
homemade galvanometer on the table
horizontally and turn it until the compass
needle is parallel to the coil of wire. Use
these bell wire ends to attach to your lemon
and paper clip.
You'll need a small baby food jar with a
lid, some rubbing alcohol, and 15 whole
cloves. Place the cloves in the jar and half
fill the jar with the rubbing alcohol. Secure
the lid and let the jar sit for seven days.
When the time is up, test the perfume using
your finger to dab a few drops of the alcohol
on your wrist. Let the alcohol evaporate and
then smell your wrist. Your skin should have
a faint, spicy aroma.
What's happening here? The alcohol
dissolves the aromatic oil in the cloves.
When the alcohol evaporates from the wrist,
the scented oil is left on the skin. Rubbing
alcohol is a dilute solution of isopropanol, or
isopropyl alcohol, in water. Perfumes are
made by dissolving oils from flowers and
other aromatic materials in alcohol. See the
March 1996 ChemShorts on "Sugar and
Spice" for more information on spices. For
example, cloves are small, round, dark
brown, dried flower-buds grown in places
like Zanzibar and Sumatra. The aromatic oil
of cloves is called eugenol (C10H12O2 ).
Cloves, like many spices, are used in
cooking and baking to enhance flavors.
Cloves are often used when baking a ham,
for example. Perhaps some cloves are left
over from your Easter ham that can be used
for your Mother's Day gift!
Reference: "Chemistry for Every Kid" by
Janice VanCleave, NY: Wiley Publ., 1989, p.
172.
You'll need a small sampling of rocks,
making sure that some of them are limestone
or marble, chalk, a few seashells, vinegar
and/or lemon juice, and some clear plastic
cups. Put the seashells in one cup, each
rock in it's own cup, and a piece of chalk in a
cup. Label each of them if necessary,
especially to keep track of the rocks. Pour
the lemon juice or vinegar over each
material and note what happens. You
should see bubbles form on some of the
materials, although not from all of the rocks.
What's happening here? Vinegar and
lemon juice are both weak, dilute acids
(acetic acid and citric acid, respectively).
Calcium carbonate is a chemical compound
found in many natural materials, such as
limestone and seashells. When calcium
carbonate is exposed to acid, it chemically
changes into new materials. One of these is
carbon dioxide gas, which form the bubbles
that you observe in the cup. When limestone
is exposed to great heat and pressure under
the earth's surface for many years, it turns
into marble. It is still calcium carbonate and
that is why marble will form bubbles with
acid also. You get similar results when
using chalk because it, too, is made of
limestone.
Reference: "Earth Science for Every Kid"
by Janice VanCleave, NY: Wiley Publ., 1991,
p. 32 and "Simple Science Experiments with
Everyday Materials" by Muriel Mandell, NY:
Sterling, 1990, p. 54.
You'll need 12 oz of water, and a
tablespoon each of milk, chocolate syrup,
and powdered xanthan gum. What in the
world is xanthan gum and where do you find
it? Most specialty health food stores and
pharmacies should have some of this
substance. When these ingredients are
mixed in a blender for a few minutes, the
result looks virtually indistinguishable from
your local fast food shake. The taste won't
be quite as good; however, you can add
more syrup, or a touch of sugar or vanilla
extract, and ice chips to make it closer.
What's happening here? Xanthan gum is
a synthetic carbohydrate polymer, similar to
natural gums. It is one of many common
thickening agents used as food additives. It
forms what is called a "hydrophillic colloid",
or small particles that can soak up amazing
amounts of water. Other examples are agar,
arabic gum, bentonite (a clay!), celluloses,
and polyethylene glycol. Look on lists of
ingredients to find these substances,
especially on "fat free" or "reduced fat"
alternatives (they replace the smoothness of
the fat). You may also find carrageenan, a
polysaccharide derived from seaweed.
Rumor has it that this is what is really used in
those fast food shakes - so much for the
actual amount of "milk" in them!
Reference: Larry Lippman on the internet
at: www.polymers.com/dotcom/pdcmag/
You'll need ice, 3 clear plastic cups,
water, a measuring cup, masking tape,
ballpoint pen, paper towels, and a really
humid day. Use the masking tape and pen
to label the cups A, B, and C. Place 1/2 cup
cold water in each cup. Wipe the outside of
the cups with the paper towels to insure they
are dry. Leave cup A alone as your control
experiment. Add one ice cube to cup B. Fill
cup C with ice until it is nearly full. Let them
sit 5 minutes. Look at the outside of the
cups. Describe what you see, then use your
finger to test for any liquid on the outside of
the cups. What is this liquid and where did it
come from?
What's happening here? You are
watching a gas change to a liquid as a result
of condensation. The liquid came from water
vapor (water in its gaseous state) in the air,
which has condensed to form liquid on the
surface of the cold cup. Does one cup seem
to have more liquid on the outside than
another? Why do you think it does?
Reference: WonderScience, 1997, 11(5).
What's happening here? You are
watching a gas being created by a reaction
in-a-glass. The baking soda, or sodium
bicarbonate (NaHCO3 ), is reacting with citric
acid from the juice to create carbon dioxide
gas. This is why you need a citrus fruit for
this experiment. All sodas get their fizz from
trapped carbon dioxide (CO2 ) bubbles,
although it is usually added via
pressurization. In other words, the bubbles
in real soda are created by carbon dioxide
gas that is added under pressure to a
solution of water and a flavored sweetener,
and that's all there is to soda-pop!
Reference: Simple Science Experiments
with Everyday Materials, by Muriel Mandell,
1989, Sterling Publishing Co., NY.
Taken From: Apples, Bubbles, and
Crystals: Your Science ABCs, by A.
Bennett & J. Kessler, 1996, McGraw
Hill, NY.
Kids, how would you like to make your
own paper? You'll need two full newspaper
pages, water, a coat hanger, an old pair of
panty hose, two spoonfuls of white glue, a
wad of dryer lint, a blender or food
processor, and a kitchen sink.
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Submitted by: Kathleen A. Carrado, Chair
of the Elementary Education Committee.
beakman/beakman.html.
Kids, how would you like to make
electricity with a lemon? You'll need a
lemon, a galvanometer, 2 stiff copper wires,
a large paper clip, and scissors.
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Submitted by: Kathleen A. Carrado, Chair
of the Elementary Education Committee.
Reference: "Simple Science Experiments
with Everyday Materials" by M. Mandell, NY:
Sterling Publ., 1990, p. 58.
Kids, how would you like to make your
own bottle of perfume? If you don't use it
yourself, it would make a nice Mother's Day
gift...
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Submitted by: Kathleen A. Carrado, Chair
of the Elementary Education Committee.
Kids, in this activity you can pretend to be
a geologist and test some rocks and other
natural materials using a common chemical
method.
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Submitted by: Kathleen A. Carrado, Chair
of the Elementary Education Committee.
Kids, in this activity you will learn how to
make a thick - a very thick - liquid. It will be
non-toxic, non-corrosive, cheap, and edible.
It will, in fact, in many ways resemble a
typical fast food restaurant milkshake.
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Submitted by: Kathleen Carrado, Chair,
Elementary Education Committee.
slime.html.
Matter is another word for the material
that makes up all the stuff in the whole world.
The three forms, or states, of matter are
solids, liquids, and gases. One very useful
thing about matter is the way it can change
between it's forms. In this activity you'll
watch matter change from one state to
another!
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Submitted by: Kathleen Carrado, Chair,
Elementary Education Committee.
Kids, you can make a bubbly lemon,
lemon-lime, or orange soda that is actually
pretty tasty. You'll need a lemon, lime, or
orange, and a glass, water, baking soda,
and sugar. This is what you do: squeeze
the juice from a lemon or orange into the
glass. If you want the lemon-lime taste, add
some juice from a lime to the lemon juice.
According to how much juice you were able
to get, add an equal amount of water. Stir in
a teaspoon of baking soda, and observe
what happens. Check out the taste, then
add sugar if you like (or some other
sweetener), tweaking the ingredients until it
tastes perfect to you. Actually, any citrus fruit
will do. If you happen to like grapefruit, you
could also try one of these alone or in
combination with one of the other fruits
mentioned.
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Submitted by: Kathleen Carrado, Chair,
Elementary Education Committee.
When Archie cuts up apples,
The slices all turn brown.
They don't look very yummy,
Which makes his buddies frown.
But Archie is a good cook
Who knows a special way
To stop the color changing
At any time of day!
Kids, if you want to test out Archie's
secret, you'll need paper towels, paper, 3
fresh apple wedges, lemon juice, and water.
Spread out the paper towels. Make a large
chart on the paper with columns of "water",
"lemon juice", and "nothing". Place the
apple wedges on the chart, one for each
column. Pour some water on the first wedge,
lemon juice on the second, and do nothing
to the third. Wait one hour and observe your
apples. What has happened? Do you know
why? When it's protective skin is gone,
certain substances in an apple will react with
oxygen in the air and turn brown. Citric acid
in the lemon juice has stopped the reaction
of oxygen that turns the apple brown. This
trick of using lemon juice, or orange juice, is
used by Archie and many other cooks to
keep apples, bananas, and other fruit
looking good for fruit salads, etc.!
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Taken From: Apples, Bubbles, and
Crystals: Your Science ABCs, by A. Bennett
& J. Kessler, 1996, McGraw-Hill, NY.
Fern the Duck catches peanuts
She eats them in a wink.
She has to catch them quickly,
Or else the peanuts sink.
Fern can give some good advice
That slower ducks should note.
Moving to saltwater helps,
'Cause there the peanuts float!
Kids, here's how you can test
Fern's theory for yourself. Use
masking tape and a pencil to label two
clear plastic cups as "fresh water" and
"salt water". Add water to each cup
until 3/4 full. Add 6 teaspoons of table
salt to the salt water cup and mix with a
spoon for a few minutes. Add a peanut
(the kind that is already shelled) to
each cup, and observe what happens.
You should see Fern's theory in action:
the peanut in the fresh water will
instantly sink while the peanut in the
salt water will float. In fact it will float all
night! Objects float if they're lighter
than the amount of liquid that they
displace, or push aside. They sink if
they're heavier. Fern's peanuts are
heavier than the fresh water that they
displace, so they sink. Dissolving salt
in fresh water makes the same amount
of liquid heavier, allowing the peanut to
float. It's the same reason that you
float more easily in the ocean than in a
lake!
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