We are totally milking it for this week’s DIY Science experiment! With just three household items, you can recreate this experiment in your own home!
You will need:
- Baking sheet with an edge
- Food coloring
- Whole Milk
- Liquid dish soap
To start this experiment, you will need to pour the whole milk into the baking pan. Allow the milk to sit for a little bit in order to settle.
Add 6-10 drops of food coloring in the colors of your choosing. Notice that the food coloring doesn’t really spread too far.
Next, add a few drops of dish soap to the food color drops and watch what happens!
What just happened?
Milk is mostly made up of water, along with vitamins, minerals, proteins, and tiny droplets of fat suspended in solution.
The secret of the bursting colors is in the chemistry of that tiny drop of dish soap. Like other oils, milk fat is a non-polar molecule, meaning it doesn’t dissolve in water. However, when you add dish soap, the non-polar (hydrophobic) portion of micelles (molecular soap structures in solution) break up and collect the non-polar fat molecules.Then the polar surface of the micelle (hydrophilic) connects to a polar water molecule with the fat held inside the soap micelle. Thanks to the soap connection, the non-polar fat can be carried by the polar water. This is when the fun begins.
The molecules of fat bend and twist in all directions as the soap molecules race around to join up with fat molecules. While this is taking place, the food coloring molecules are moving around, providing an easy way to observe all the invisible activity. As the soap becomes evenly mixed with the milk, you will see that the action slows down and eventually stops.
For this reason milk with a higher fat content produces a better explosion of color—there’s simply more fat to combine with all of those soap molecules!
Give it a try!
It is important to note that an experiment uses a variable (something that changes) to answer a question. To turn this demonstration into an experiment, you have to change something! Check out these ideas to get you started:
- What changes do you notice when you use a different type of milk (such as skim, 1%, 2%, Almond, etc)
- How do different brands of dish liquid react in the milk/food coloring?
Try it and let us know how your experiment turned out on our Facebook, Instagram, or Twitter page using the hashtag #gscscience!
This experiment was recreated from stevespanglerscience.com