Making Oobleck at Home: Fun with Physics!

Age: Grades 4-6

Prep Time: 10 minutes

Activity Time: 30-60 minutes

Materials:

• Water (1 cup)
• Corn Starch (1 1/2 - 2 cups)
• Food Coloring (optional)
• Large Bowl
• Mixing Spoon
• Container (Large enough to fit 4 cups)

Step-by-Step Instructions:

• Add water to the bowl.
• Add the corn starch in small amounts to the bowl. Begin mixing with the mixing spoon and eventually you may use your hand.
• Continue mixing until the consistency of the Oobleck reaches a consistency that is both liquid when poured but also solid when grabbed. It should be a gooey consistency, not powdery and not wet in the sense that it will splash when hit.
• Add food coloring to the Oobleck and thoroughly mix with your hand.
• Play with your Oobleck! See Suggested Activities below.
• Store your Oobleck in an airtight container to save for later!

 Suggested Activities:

• Try stirring the Oobleck. Stir quickly, it should act like a solid and resist. Stir slowly, it should act like a liquid and give way.
• Grab a handful of Oobleck, squeeze it, and let it flow out of your fingers.
• Slowly dip your and into the Oobleck (It should act like a liquid).
• Punch the Oobleck (It should feel solid).
• Shake your Oobleck in a container.
• Compare Oobleck to solid water (ice) and liquid water.
• Design other experiments to test how Oobleck behaves like a solid or a liquid, record your findings!

Photo credit:  David Mudler (Flickr)

Key Information:

• Everyday materials generally fit into one of three states of matter: Solid, Liquid, Gas
  • Solid – Definite shape and volume; rigid; not easily compressible; does not flow easily
  • Liquid – No definite shape, but definite volume; non easily compressible; flows easily
  • Gas – No definite shape or volume; assumes the shape and volume of the container it is in; compressible; flows easily
• Sir Isaac Newton proposed that fluids flow at a predictable, and constant rate. Many fluids, such as liquid water, behave this way.  Oobleck does not behave this way.
• Oobleck is a non-Newtonian fluid that has properties of both liquids and solids. This means that it acts like a liquid when being poured, but like a solid when a force is acting on it.
  • Non-Newtonian fluids respond differently depending on how quickly you try to move them. Non-Newtonian fluids act as liquids when moving slowly but like a solid when moving quickly.
• Oobleck gets its name from Bartholomew and the Oobleck by Dr. Seuss.
• Other common non-Newtonian fluids include, ketchup, mayonnaise, and jelly. What other non-Newtonian fluids can you find around your home?