With summer winding down, the temperature outside is still rising and your inspiration for kid friendly activities is wearing thin. We come to your aid offering the M&M rainbow experiment. I especially like this one because it’s quick and easy. So easy in fact, it will probably take you longer to read this post than to do the experiment. If you are like us a quick dig into the back of the pantry you will probably unearth a few crusty old packs of M&M’s leftover from Halloween. Obviously, they are not going to be eaten so this is a way to put them to good use.
Is it science or is it magic? Well that all depends on you. If you are looking to provide a learning experience you can discuss solubility, dyes, and visible spectrum. Roy G Biv anyone? If you are tired and just looking to have fun, tell them you know a really, cool magic trick because what is better than magic and rainbows? Unicorns….that’s the only thing better.
All you need is M&M’s (we used plain), a flat plate with a lip on the edge (we used ceramic), a level surface and a cup of room temp tap water. Place your plate on a level surface, arrange M&M’s around the perimeter of the plate forming a closed circle. When choosing a plate make sure it is sturdy and flat. If it bows up in the center your colors will struggle to run to the center. If you are working with small children, we suggest using an appropriately sized pitcher or a liquid measuring cup with a spout on it for greater accuracy when pouring the water. Next, pour water into the center of the plate quickly, but gently until the water touches all sides of your candy circle. Be sure not to bump or move your plate at any time once you have begun pouring the water. The candy colors will quickly begin to run toward the center of the plate. It only takes a minute or two. At the point your rainbow is completed it will only stay nice for a few minutes. The colors will continue to bleed together so enjoy it for the short time it lasts.
Here’s the scoop, we prefer science over magic and unicorns on most days so here is a basic cheat sheet for things you can discuss during your experiment.
Solubility– The ability or better known as a chemical property of a substance to dissolve into another substance. In this case M&M’s are water soluble, meaning the candy shell can dissolve into water. There are three major components of solubility, a solute and a solvent which results in a solution. For our experiment the candy shell is the solute, the part that dissolves. The solvent is the water. Water being the substance that the solute dissolves into. When you dissolve a solute into a solvent you are left with the final product, a solution. Now that we know how the process of solubility works; what does that mean for our candy? Basically, the water particles surround the sugar bonds on the candy shell of your M&M’s loosening them and spreading them apart. A process you wouldn’t normally be able to see with your naked eye but because the candy shells contain dyes or colors you can see them becoming bonded with the water molecules as the colors are pulled to the center of the plate.
Dyes– Dyes are groups of compounds that are used color to something else. Natural dyes can be found all over your kitchen. Cabbage, beets, carrots and turmeric are just a few.
Visible Spectrum– Your M&M’s appear a certain color because of the wavelength of light it absorbs at various frequencies. Each frequency range determines the colors you see but wavelengths are more measurable for scientific purposes. Here’s an example of wavelengths, the human eye can see wavelengths measuring 380-700 nanometers. Violet has the shortest wavelength and red the longest. As a full spectrum of colors gives off different wavelengths you become able to distinguish each color of the rainbow separately. The easiest way to think of way think of this concept is objects don’t give off color but the light they give off registers as color to the human eye. There are seven ranges of wavelengths on the visible spectrum that allow you to see the colors of the rainbow, red, orange, yellow, green, blue, indigo and violet. This is very a basic overview of a complex topic. By no means are we physicists, so if you are looking for more information we would suggest visiting Nasa to learn more about visible light.
Roy G Biv– The acronym used to represent the colors of a rainbow. Red, orange, yellow, green, blue, indigo and violet. It’s an easy way to learn the colors of the rainbow and super fun to say.
Now that the science lesson is over, we hope that you enjoy the experiment! Please, share your story down below or tag us on social media so we may see your results.