Inspired by Dr. Seuss' Bartholomew and The Oobleck, we conducted a science experiment by creating the mysterious green substance known as Oobleck, which has both solid and liquid properties! That is, if you pour it or dip your fingers in it, it acts like a liquid. But if you squeeze it, push it, or otherwise apply pressure to the mixture, it acts like a solid! Want to "walk on water"? Make enough Oobleck to cover your floor! (Disclaimer: this is not recommended, as clean-up may require a visit from the Cat in the Hat.)
This program was met with much excitement and enthusiasm, which I think is to be expected for anything involving "green slime". I began the program by book talking Bartholomew and the Oobleck, and then read the Royal Magicians' magic spell aloud (paragraph 32):
Oh, snow and rain are not enough!
Oh, we must make some brand-new stuff!
So feed the fire with wet mouse hair,
Burn an onion. Burn a chair.
Burn a whisker from your chin
And burn a long sour lizard skin.
Burn yellow twigs and burn red rust
And burn a stocking full of dust.
Make magic smoke, green, thick and hot!
(It sure smells dreadful, does it not?)
That means the smoke is now just right
So, quick! Before the day gets light,
Go, magic smoke! Go high! Go high!
Go rise into the kingdom’s sky!
Go make the oobleck tumble down
On every street, in every town!
Go make the wondrous oobleck fall!
Oh, bring down oobleck on us all!
I mixed up a batch of Oobleck myself, explaining the ingredients and measurements as I went along. As I poured a bit in each child's plastic cup, I asked them if they thought it was liquid or solid. Most of them guessed liquid. Then I asked them to pick up some of the Oobleck and try to roll it into a ball. "Is it still liquid?" I asked. They got very excited when they realized that it was both a liquid AND a solid- the scientific term for which is "non-Newtonian". Lots of experimenting ensued.
I was glad I did not allow each child to mix up his/her own batch- it actually takes a bit of trial and error to get the exact right consistency; and the mess I was left with after the experiment was plenty. It looked much worse than it actually was, however. Since Oobleck is just cornstarch and water, I waited until it dried and vacuumed it right up out of the carpet. Tables and chairs needed a simple Clorox wipe.
I was glad I did not allow each child to mix up his/her own batch- it actually takes a bit of trial and error to get the exact right consistency; and the mess I was left with after the experiment was plenty. It looked much worse than it actually was, however. Since Oobleck is just cornstarch and water, I waited until it dried and vacuumed it right up out of the carpet. Tables and chairs needed a simple Clorox wipe.
I sent each child home with a handout including the following recipe and and experiment ideas, along with this coloring sheet from Seussville, one of my favorite websites on the interwebs. The coloring sheet was also a nice supplement for toddling little brothers and sisters who were too young to participate in the experiment (intended for children ages 6-12).
Oobleck Recipe!
Oobleck Recipe!
Ingredients:
- 1 cup water
- 1.5 - 2 cups cornstarch
- Green food coloring
Mix water, cornstarch, and food coloring in a bowl. Start with water and add cornstarch slowly until your Oobleck is the right consistency: it should feel a little but like honey and tear a little if you drag your fingers over it.
Experiments:
- Form Oobleck into a ball, then let go, letting the mixture run between your fingers.
- Pour Oobleck onto a plate and slap it with your hand.
- Try to form Oobleck into a shape. Can you make it stay that way?
- Drop different items into Oobleck (pennies, paperclips, popsicle sticks) – do they float or sink?
- Poke the Oobleck quickly. What happens? How does it feel?
Continue Experimenting at Home:
- What happens when you put Oobleck in the Freezer?
- What happens when warm up Oobleck in the sun?
- Put Oobleck in both a sealed and an unsealed container on the window sill. What happens over time? Draw illustrations of the results.
- Make Oobleck with different variations of ingredients: hot water, cold water, more water, less water, more cornstarch, less cornstarch, etc. Are the new mixtures’ properties any different?
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