With the near-constant buzz about American students falling behind much of the rest of the world in math and science scores, you might be wondering how you can boost your own child’s science and math literacy. Experiments from the Wisconsin Initiative for Science Literacy make family science nights simple affairs that can't help but arouse curiosity -- as the world is a much more interesting place when you understand some of the things happening right under your nose.
Add a little science and math to your evening meal. Before preparing a recipe, sit down together and do the math needed to double it, teaching your child the importance of understanding fractions. As a bonus, you might have leftovers for tomorrow’s lunch. The beverage for this meal is dancing raisins. Fill tall glasses with sparkling soda, dropping six raisins into each. Invite your child to keep a close eye on the glass, noticing how the raisins -- denser than water -- sink at first, only to be surrounded by carbon dioxide bubbles that eventually carry them to the surface. Try this with other fresh or dry fruit.
Before serving M&M’s for dessert, use chromatography to uncover the dye combinations used to create the candy’s colors. With a ruler and scissors, measure and cut a white paper coffee filter into a 3-by-3-inch square. Draw a line 1/2 inch from one edge, marking six evenly spaced dots on the line that begin about 1/4 inch from each edge. Select six different colors of M&M’s, labeling each dot with a corresponding and abbreviated color name. Put an 8-by-4-inch piece of aluminum foil on the counter, spacing six water droplets on it and setting one of the candies in each droplet. Once the colors have leaked into the water, remove the candy. Moisten a toothpick in one of the colored droplets, touching the damp end to the corresponding dot on the paper filter (matching yellow to yellow, etc.). Repeat this step for all six colors, using a clean toothpick each time. Repeat the entire process two more times, until each dot on the paper gets three drops of colored water carried over on a damp toothpick. Fold the paper in half, standing it on end with the colored dots on the bottom.
While the paper is drying, pour 1/8 teaspoon of salt and 3 cups of water into a clean milk jug, shaking it to dissolve the salt. Pour 1/4 inch of this solution into a tall glass, setting the folded paper in the glass so that the dots are above the solution. As the solution slowly creeps up the paper, the colors will separate into different bands, revealing the dye combinations used for each. Let the experiment continue until some of the colors are the roughly 1/2 inch from the top. Pull the paper out, continuing to examine it. Through chromatography, you can see that some dyes had more affinity for the salt solution and traveled further up the paper, while others had more affinity for the paper and stayed closer to the bottom.
While your family is cleaning up after the meal, take a detour into the effects of static electricity and bend some water. This works best in low humidity. Pick the person with the longest hair and run a plastic comb through it several times. Turn the kitchen faucet on so only a trickle of water is coming out -- around 1/16-inch thick. Move the comb closer and closer to the water -- without making contact -- watching the water bend toward the comb. Run the comb through the hair a few more times and repeat the experiment, noticing that the water bends even closer. Rubbing the comb against the hair developed a positive electrical charge as electrons jumped from surface to surface. Now positively charged -- and missing some of its electrons --the comb attracts molecules from the free-flowing water spilling out of the faucet.
“Polishing” the Silver
Silver polishing has never been easier with this bit of scientific magic -- undoing the chemical reaction that attached airborne sulfur to the silver, blackening it. Line the bottom of a large dish with aluminum foil and enough water to completely cover your silver. Measure the water’s volume cup by cup as you pour it out of the dish and into a pot, bringing it to a boil. Remove the water from the heat, placing it in a sink to catch any of the foam created by stirring in baking soda in the ratio of 1 cup baking soda to every gallon of water. Work out the proper ratio together. With the silver in direct contact with the aluminum, pour the salt solution over the silver, watching the tarnish disappear before your eyes. Unseen, a small electric current is forming as the solution transfers the attached sulfur away from the silver and onto the aluminum, where it either bonds to the surface or forms into tiny flecks.