It’s October--the leaves are changing colors, the weather is getting cooler, and you are probably starting to see all kinds of gourds and pumpkins at the grocery store. These days, people seem to like pumpkin flavored ANYTHING. Today, we aren’t going to eat any pumpkin, but we ARE going to use a pumpkin in our science activity to create PUMPKIN SLIME!
When we create pumpkin slime, we are going to follow similar instructions for the first version of slime that we concocted. In this version, the special ingredient for creating slime is cornstarch.
The slime that you will be making is called a non-newtonian fluid. Newtonian fluids, such as water, do not provide much resistance when stress is applied to them. If you jump in a pool, the water gives way. Non-newtonian fluids change their viscosity or “flow behavior,” when stress or pressure is applied to them. Simply put, this means that the slime acts like both a liquid and a solid. When you poke it or pick it up and roll it into a ball, it feels like a solid. When you stop playing with it, it runs through your fingers like a liquid. Can you think of other substances that might sometimes act like a liquid and sometimes like a solid?
Check out this video about non-newtonian fluids to see them in action!
According to the link you just read, what other substances besides slime or “oobleck” are non-newtonian fluids? Can you think of any others?
Now that you know a little bit about the science behind the slime, let’s get started!
- One pumpkin
- Mixing bowl
- Cookie sheet or pan
- Food coloring (optional: your pumpkin will already color your slime an orangey tint)
Here’s what to do!
- Cut the pumpkin in half and clean out the guts and seeds with your hands or a spoon. Put all the pumpkin innards into a mixing bowl. How do the guts feel? Look? Write down your observations.
3. Measure 1 cup of cornstarch and pour it into the bowl with the pumpkin guts and mix with the spoon until well-blended. What does your mixture look like now? How has the consistency changed? Record your observations.
4. Optional: add about six drops of food coloring and stir it in.
5. Place the pumpkin half on a pan or cookie sheet with the hollow part facing upward (The pan is just to keep your play area clean).
6. Now that you have your pumpkin slime all ready to go, dump it back in the pumpkin half for goopy fall play!
7. Have fun! Pick up your pumpkin slime and play with it! What does it feel like? Look like? Is this what you expected to happen?
Extension: Try adjusting the amount of water, glue, or starch to see how it changes the quality of the slime.
Moore, K.T., 2015. Silverman's Farm. File uploaded from Wikimedia Commons on 10/3/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Silverman%27s_Farm.jpg/800px-Silverman%27s_Farm.jpg File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license. No changes were made.
The Discovery Slow Down, 2013. Non-Newtonian Liquid IN SLOW MOTION! Video uploaded from YouTube on 10/3/2016. https://youtu.be/G1Op_1yG6lQ
2009. Pumpkin2007. File uploaded from Wikimedia Commons on 10/3/2016.
https://upload.wikimedia.org/wikipedia/en/d/d8/Pumpkin2007.jpg File released into Public Domain.
BradBeattie, 2006. Pumpkin seeds in hand. File uploaded from Wikimedia Commons on 10/3/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Pumpkin_seeds_in_hand.jpg/800px-Pumpkin_seeds_in_hand.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.