This is science at its best: hands-on, interesting and full of concepts that become deliciously clear.
What You'll Need:
- 1 package plain M&Ms per child
- 1 glass of water
- white coffee filter
- paper and colored marking pens
Your child should first feel the package of M&Ms before it is opened and make an estimate of how may candies are in the bag. Write down the estimate. Open the package and count the number of M&Ms. Write down the actual number. Now, you are going to make a graph. Across the top of the paper, write down the different colors of candies and draw lines down the paper separating each column. Find colored marking pens that match the colors of candies. With each candy counted in the color categories, make a mark with the pen. Don't eat them yet!
When the graph is finished, it is time to move on to the science of chromatography. Cut the coffee filter into two long sections. Next take two yellow, two green and two light-brown M&Ms and place them on a small saucer. Take two red and two dark-brown candies and place them on another saucer. Add one teaspoon of water to each saucer and stir the candies around in it until all the color is washed off. Now you can eat the wet ones! Take a strip of filter and place a third of its length onto the colored water of one saucer; repeat with the other strip of filter. Leave overnight or for several hours.
What happens? The dyes in the candies are absorbed by the filter at different rates, causing them to separate again on the filter (they will not separate into exactly the same colors of your M&Ms, however). This process is called "chromatography." Even though the colors were mixed together physically, the atoms and molecules actually remain separate in the water. Chromatography is the process that demonstrates this concept.