ChemShorts for Kids   --   1998
Copyright ^©1998 by the Chicago Section of the American Chemical Society

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!

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.

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.

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.

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.

Updated 2/22/99