Ooooh! Oobleck!

I can’t believe it’s taken me so long to make oobleck with my superheroes!  The first time I ever heard about it was during a teacher workshop at the Exploratorium in San Francisco and then I forgot about it for years.  Until this summer.  If you’ve never made this stuff before, YOU HAVE TO!  It is the coolest thing you have ever felt!  And it only requires ONE ingredient (besides water).  So open up your pantry and make some TODAY!

Here’s what you’ll need to get started:

  • Cornstarch
  • Water
  • Food coloring (optional)
  • Shallow bin or rimmed baking sheet (we used a shallow Ikea bin)

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Add about 4 cups of cornstarch to the bin.  Let your superheroes touch it and feel it with their fingers.  Ask them how it feels.  We talked about the cornstarch being a solid.

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We talked about the water being a liquid and how it is different from a solid.

Then, we added about 2-2.5 cups of water.  Let your superheroes mix it with their hands. (You will know that you have the right consistency when you apply pressure to it, it will feel hard, but your fingers will still be able to glide easily in it, like water.

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This is the coolest thing you have ever felt!  It feel like clay when you pick it up.  But then turns into liquid immediately.  Try making a ball.  The picture on the left is me trying to make a ball.  When I opened my hand, it just oozed out!  The boys tried to scrape it off the bottom of the bin but it crumbled and then liquified.  We discussed whether they thought this was a solid or a liquid.

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Then we decided to kick it up another notch. Food coloring!

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The superheroes REALLY loved this part.  We added red.  And then we added some green.

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This was so much fun!  My oldest superhero said it felt like he was wearing a glove.  Even Daddy stopped by to check out the fun and was mesmerized by the oobleck!  And as it dripped down, it left a thin film on our hands which we easily scraped off.  It washes off immediately and easily with some water.  We will definitely be doing this again!

**NOTE** Do NOT pour the oobleck down the drain! Either throw it in the trash OR let the water evaporate and re-use the cornstarch to make another batch of oobleck.

The Science behind the Activity:

Oobleck is a pressure-dependent substance (Non-Newtonian fluid, for you science buffs) much like quicksand.  Apply pressure to it and turns hard; release and it liquifies.  By applying pressure, you force the cornstarch particles together and it reacts similar to clay (a solid) and by releasing the pressure, your hands can slide easily in between the particles.

And here’s a cool factoid: Oobleck gets its name from abook by Dr. Seuss called “Bartholomew and the Oobleck”

For a fabulous explanation of how oobleck works and more details, follow the link below:

https://www.exploratorium.edu/science_explorer/ooze.html

 

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