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.
Taken From: Apples, Bubbles, and
Crystals: Your Science ABCs, by A.
Bennett & J. Kessler, 1996, McGraw
Hill, NY.
February, 1998
Magic sand was developed by chemists at Cabot Corp. with the idea that it could be used to cleanse water of oily contamination. Many materials that are water-hating, like magic sand, are oil-loving. When sprinkled on an oil slick, magic sand attaches to the oil, adds weight, and sinks. This theoretically allows oil to be dredged from the bottom and saves the coasts from an oil slick. It has also been tested by utility companies in the Arctic. When a junction box is covered with magic sand, buried lines can be serviced easily because the dirt does not freeze and remains dry and loose year round. Other proposed uses: a surface for horse-racing tracks, in golf course sand traps, in children's sandboxes, and around the foundations of homes.
There is a product available in toy stores called Sqand (RoseArt), for ages 6+, that is based on the principle of magic sand if you would like to give it a hands-on try for yourself. It is colorful, safe, non-toxic, and fun!
Reference: ChemMatters, April 1994, "Magic Sand" by D.
Robson.
May, 1998
Food is the body's fuel and, like a car needs gasoline, your body needs food to make energy and keep going. A balance of food from the major groups is essential to good health, and it's important to give your body enough food every day. However, too much of one type of food can backfire, so you need a balanced mix. Take fat, for instance. Fat cushions your body, keeps you warm, and gives your body lots of energy. Your brain is about 60% fat! Eating fat is important but too much can make you... well... fat. To get an idea of the presence of fat in your meals, try this fat-sensor experiment.
Cut a brown paper grocery bag into squares and label them with foods you want to test. Rub each different food onto their labeled squares. Although fun, there is no need to mash the food into a pulp. Set the squares aside for about 30 minutes, then hold them up to a light. It should be "clear" which foods have the most fat, for they will leave oily spots that are virtually transparent.
Reference: "Bill Nye, The Science
Guy's" website is: http://www.billnye.com/.
June, 1998
The table has information about every element found on Earth. After many years of studying chemical elements, scientists have discovered or created over 100 different elements. Every gas, liquid, solid, rock, metal, compound, and mixture in the universe is made up of some combination of these basic elements. In the typical periodic table, elements with common properties fall in the same column. The overall arrangement makes sense to chemists but it is highly technical and not very approachable for the young or non-scientist. Everyone can have fun with it, however, when a different and more light-hearted approach is taken.
One such presentation distorts the shape of the boxes of each element to reflect its relative abundance on Earth. This way the largest boxes contain the most commonly known elements, such as those for C (carbon), O (oxygen), and Si (silicon). Check this out in the Journal of Chemical Education, volume 70, page 658, August 1993. A sample chart with a full activity's description for elementary school students and teachers is provided.
In addition to this, some colorful charts for
display can be ordered from various places, such
as Aldrich Chemical Co. (800-558-9160), Gelest
Inc. (215-546-1015), La Naturaliste in Canada
(418-724-6622), and Time-Life Books published a
giant poster in 1987. A company called "Food for
Thought" will provide posters for "eaters and
thinkers" of food items, vegetables, desserts or
even animals in take-offs of the original (800-666-
5436). Have your parents or teachers check into
these for you!
Finally there are the mixtures. These are combinations of compounds and
account for most of what you encounter during the day. Take salt water, for
example. Mix some regular table salt in water and you have a mixture. It is
not a new compound because you can't write a formula for salt water, rather it
is a combination (a "homogeneous" one). Mix together salt with some white
table sugar and you also have a mixture (a "heterogeneous" one). White sugar
is a pure compound called sucrose. Other examples of mixtures are: milk
(water, milk fat, proteins, lactose, etc.), blood (white blood cells, red blood
cells - with hemoglobin molecules, water, platelets, electrolytes - salts,
etc.), and dirt (silica or silicon dioxide or sand, decayed plants, moisture or
water, etc.). It is much easier to make a mixture than it is to make a pure
compound! Try to find some more examples of mixtures and compounds during a
regular day.
------------- By: K. A. Carrado, Chair of Elementary Education
Committee.
Tannins are actually a class of organic compounds, some of which
are used to "tan" hides into leather, and some are used in inks and
dyes. The brown color of tea is also due to flavonoids, which are
organic molecules that are natural pigments. Volatile oils give the
flavor. About 2-5% of tea leaves is caffeine. An average 5 oz cup
of tea contains 25-75 mg caffeine (some people prefer decaffeinated
or herbal teas instead).
The tea leaves are picked by hand, left to wilt, then rolled and dried.
If they are allowed to ferment before drying, you get black tea.
Partially fermented leaves gives oolong tea, and tea not fermented
at all is the so-called green tea. The tea plant is a relative of the
camellia, so botanists have named it "Camellia thea". It is an
evergreen shrub or tree 9-60 feet high. The first indisputable
reference to the medical use of tea is from a Chinese dictionary in
350 A.D., but some folks even say there is evidence that a Chinese
emporer used it all the way back in 2737 B.C. And, since it is native
to Indochina and India, tea was grown for drinking even before China
used it as a medicine.
-------------
K. A. Carrado, Chair of Elementary Education Committee.
It's not too hard (ha ha, get it?) to make your own fossil. First you'll need to cut a small sponge into a bone-like shape using a pair of scissors. Then fill a big bowl with enough sand to bury the sponge, and make sure it's completely covered. While stirring, add enough salt to a pitcher of water until the water becomes murky. Pour this salty water into the bowl of sand until it's thoroughly wet. Put the bowl in a sunny place. This really needs a lot of sunlight so it will take at least a week. Maybe even a few more days if the days are getting shorter and there is not so much sunlight. When at least 7-10 days have passed you can dig up the sponge. In this experiment the mineral that hardens the spongy bones into hard fossils is salt (sodium chloride).
Did you know that blue whales are even bigger than the biggest dinosaur, the brachiosaurus, which was 35 tons and 46 feet high? The smallest known dino was compsognathus; at 15 pounds it was about the size of a chicken. Excavate these recent books about dinos from a library: "The X-Ray Book of Dinosaurs" by K. Severin (Franklin Watts Pub., 1994), "Dinosaurs: Strange and Wonderful" by L. Pringle (St. Martin's Press, 1995), and "Inside Dinosaurs" by T. Dewan (Doubleday, 1993).
------------- This column is for you real little ones - those of you who have just begun school and are learning your letters. You will learn the letter "D, d" with the basic scientific concept of dissolving something. Get a clear plastic cup, water, a pencil, a paper towel, a twist-tie, and a kool-aid packet. Carefully cut the paper towel into four equal squares. Place about one teaspoon of Kool-Aid in the center of a square. Fold it shut and close it with a twist tie. Tie the ends of the twist tie around the center of a pencil. The pencil acts as a support rod to dangle the kool-aid packet into the empty cup - just place the pencil down lengthwise on top of the cup's opening. Pour water into the cup until it just touches the bottom of the packet. Observe for a while, then add some more water. Write your name on a sheet of paper and a title: "D d Dissolve" to practice your "d's". Then draw pictures of four simple cups. On two of them, draw your pencils and packets as well as you can. Draw in water levels on all four cups. (Or your teacher or a parent can have these already drawn for you). Now draw what happens when (1) the packet barely touches the water (2) the packet is soaked in water (3) when crystals are sprinkled directly to the water (no packet), and (4) after some time has passed. Using the paper towel, a type of "schlieren" effect occurs, like when heat waves are seen over a hot surface. You can also try other materials to test whether or not they will dissolve, such as table salt (yes), sugar (yes), or sand (no). Thanks and acknowledgements to Marlisa Ebeling, a primary level teacher in Naperville District 203.
-------------
Submitted by: K. A. Carrado, Chair of Elementary
Education Committee.
Kids, sometimes it can be hard to figure out what someone means by a pure
compound versus a mixture. Let's try to clear this up with an easy explanation
and experiment. First, pure elements are what you see on the periodic table,
and some materials exist naturally in their pure elemental form, like lead
(Pb), neon (Ne), iron (Fe), etc. Some other elements are "diatomic", like
nitrogen (N2 ), oxygen (O2 ), and hydrogen (H2 ) in their natural state. Then we have to deal with the compounds. These are pure materials made up of two or more elements on the periodic table and represented by a distinct molecule, like water (H2O) and ammonia (NH3 ) and sodium chloride
(NaCl) salt.
Kids, there are all kinds of interesting things to think about when
someone dips a teabag into a cup of hot water to make their hot tea.
Inside a teabag are the crushed up dried leaves of the tea plant.
Most of a tea leaf is cellulose, which is the major structural material
of all plants. Cellulose is a very long chain (polymer) of glucose
molecules and it is does not dissolve at all in water. The tea
molecules that will dissolve in water include tannins, flavonoids,
and caffeine. In order to separate the molecules you don't mind
drinking from the leaf pieces, a teabag is used. Did you ever see
a coffee filter? The teabag material is a lot like that. It is a porous
paper that can get wet but is strong enough to not break and let the
leaves go through. So, in making a cup of hot tea you are also doing
an extraction and a filtration - these are two tools that chemists use
to isolate compounds. Try it yourself! You can also cut open a teabag
and take a look at leaves before and after.
Kids, dinosaurs didn't write memoirs or take family photos. But scientists can dig up the real dirt about dinosaurs, thanks to fossils. The only proof scientists have of dinosaurs is their fossilized bones. Original bones are
relatively soft and fragile things that cannot survive the test of time, especially not the past 65 million years when dinosaurs once lived. But luckily for us, when some dinos died their bones were covered by mud, rock, or sand. Under this protection and through the years of soil erosion, the bones absorbed minerals from the earth. These minerals made the dinosaur
fibulas, mandibles, and other bones very, very hard and resistant to erosion.
Thanks and acknowledgements to: "Bill Nye: The Science Guy" at nyelabs.kcts.org Submitted by: K. A. Carrado, Elementary Education Committee.
Updated 5/21/09