Oobleck

Concept: Non-Newtonian Liquid
Viscosity is the measurable thickness or resistance to flow of a fluid. Sir Isaac Newton theorized that viscosity is a function of temperature. Non-Newtonian liquids are fluids that change in viscosity when stress or force is applied, not when heat is applied.

Read Aloud: Crazy Concoctions by Jordan D. Brown

Ingredients:

      ·         ½ cup Cornstarch

      ·         ¼ cup Water

      ·         Food Coloring

Demonstration:

      ·         Pour ½ cup of cornstarch into a plastic cup.

      ·         Pour ¼ cup of water into a separate plastic cup. Add a few drops of food coloring.

      ·         Slowly pour the water into the plastic cup containing the cornstarch. Gradually mix the water and the cornstarch together. Continue adding water to the cornstarch until the mixture has the consistency of honey.

Experiment:

·         Does the viscosity of the oobleck change if heat is applied to it?

·         Does the viscosity of the oobleck change if pressure is applied to it?

Observations:
Oobleck acts like a solid sometimes and a liquid at other times. This concoction is an example of suspension - a mixture of two substances, one of which is finely divided and dispersed in the other. In the case of oobleck, it is a solid dispersed in a liquid.