A couple of weeks ago my husband and son were quarantined due to being exposed to someone in our family who tested positive for COVID-19. And do you want to know what that meant for me? I got to play homeschool teacher again!! Oh joy…..
And in an effort for us all not to go completely off the rails during this brief return to home school life, I did my best to come up with activities to keep us busy and engaged in learning.
After a bit of Pinterest research, I stumbled upon an experiment that looked easy enough to do and didn’t require any extravagent supplies. (in fact, I already had everything on hand that we needed! Score!)
It’s called the Magic Milk Experiment, and I have to admit, I even thought it was pretty cool!
Here’s all you need to give this activity a try:
- 1 1/2 cups of milk
- Liquid food coloring
- Dish soap
- Cotton swabs
- Dinner plate or shallow dish
- Small container
And here’s the instructions:
- Pour about 1 tablespoon of dish soap into a small container
- Pour milk onto a plate (it’s ok if you see some bubbles)
- Drip a few drops of food coloring into the center of the milk. Feel free to get creative with where you place the drops. (It doesn’t matter what colors you use, but contrasting colors will create a more obvious design.)
- Dip a cotton swab into the dish soap and then place the cotton swab in the middle of the milk where you put your drops of food coloring. Then watch what happens!! (You should see the colors start to spread out to the edges of the plate, mixing and creating a really cool design!)
- Tip: Kids can mix and swirl the cotton swab around until the milk mixture will eventually mix into all one color.
- Repeat as many times as you wish!
- When finished, dispose of the milk in the sink.
If you want to use this activity as a learning opportunity, make sure to discuss with your child a little bit of the science behind what makes it work! Here’s a basic run-down of why the Magic Milk Experiment works!
The Science Behind the “Magic Milk” Experiment
Milk is made up of mostly water, with a little bit of fat in it, along with other nutrients like vitamins, mineral, proteins, etc.
The fat in the milk is in the form of small little droplets, held in solution in the water. This means, that the molecules of fat are suspended between molecules of water. And this fat, (as well as the proteins) are very sensitive to any changes to the milk.
So, when you first add the food coloring to the milk, it kind of just sits on top of the milk, not moving much. This is because they are being held there by the water tension in the milk, on the surface.
But, when you add the dish soap, it causes a chemical reaction that makes the color droplets move around the milk and mix together. This is because the soap lowers the surface tension of the milk, allowing the colors to move about more freely and mix together.
So, how does the soap lower the surface tension? A couple of things are happening. First, the soap is reacting with the proteins in the milk. When the soap and proteins interact, the soap makes the proteins change shape, which sends them swirling around, thus causing the color to swirl too!
Secondly, the soap is also reacting with the fat in the milk. The soap and fat want to join together in pockets called “micelles” (this is how soap lifts the grease off your dirty pans!), and this causes movement as well.
Eventually, everything settles and reaches an equilibrium and the reaction ends. The reaction really had nothing to do with the food coloring in particular, it is just what allowed us to see the chemical reaction between the soap and the milk fat and proteins! And it was sure fun to watch!
So there you have it! Do you feel a little smarter now? 😉