Atlanta, Ga. (CBS46) -- The Atlanta Science Festival is an annual weeks-long celebration of science and technology.
Dr. Doug Mulford is one of the scientists who was looking forward to wowing crowds of eager kids with science experiments this weekend at Exporation Expo in Piedmont Park.
This year, the festival was cancelled amid fears of the coronavirus. Dr. Doug Mulford met up with CBS46's Molly McCollum today at a chemistry lab at Emory University to share a few simple experiments you can do with products you have around the house.
- Food coloring
- Dish Soap
- Q-Tip or Cotton Swab
- Bowl or Shallow Dish
1. Pour the milk into the bowl or dish until it covers the bottom.
2. Add drops of food coloring to the milk. Use as many colors as you want! Do not mix or stir the milk and food coloring.
3. Put some dish soap on the end of the cotton swab. Place the cotton swab in the milk and watch the colors dance around in the dish!
The secret to this experiment is the dish soap! Milk is made up of water and fats. The dish soap separates the water and the fat in the milk. The food coloring allows us to see that separation and also makes a cool dish of milk with dancing rainbow colors. You can repeat the experiment with different types of milk (1%, 2%, whole) and get different results!
OOBLECK: MAKING A NON-NEWTONIAN FLUID
- This experiment is best for outside because it's messy!
- In a container, combine 1/4 cup of cornstarch and 1/8 cup of water. Stir. If the mixture is too watery, add more cornstarch.
- Use your hands to scoop up some of the mixture. Notice how if you hold your hand out flat, the mixture oozes back into the container. If you squeeze the mixture into a ball in your hand, it becomes a solid that you can tear apart.
The mixture created is a non-Newtonian fluid also called "Oobleck." It breaks the rules outlined for the behavior of fluids by Sir Issac Newton, meaning the atoms can act as both a liquid and a solid. The best way to understand what is happening is think of trying to move through a crowd. If you were to walk slowly, you would be able to weave your way through the crowd. However, if you were to try to get a running start, you would likely come to an abrupt stop because of all the people in the way. If the atoms move slow enough, they allow the mixture to act like a fluid that you can pour. If you try to manipulate the Oobleck too quickly, the atoms act as a solid. Ketchup is also classified as a non-Newtonian fluid!
- White Coffee Filters
- Cup of Water
- Pinch of Salt
- Pipe Cleaners
- Use the markers to draw at the base of the both sides of the coffee filter.
- Put a small amount of water in a cup, just enough to cover the bottom. Add a pinch of salt to the water.
- Put the decorated edge of the coffee filter into the water and leave. Watch as the colors work their way up the coffee filter.
- Once you are satisfied withe colors, take the filter out and let it dry.
- Cut the edges off the filter to open it.
- Use the pipe cleaners to create a colorful butterfly!
The ink in markers is not just made of one color but rather it is made of several different colors! In this experiment, we are separating those colors with the water. As the water hits the colors, it carries the ink molecules with it as it spread across the coffee filter and separates them. This is a very basic example of paper chromatography, which is a common technique used by chemists to separate chemicals from a mixture. Try using different colors and types of markers to get different results!