Hands-on learning awaits...

Looking for something to do at home with your kids during the holiday break? Why not make some Holiday Slime?

You will need:

  • 1 cup of cornstarch
  • 2 cups of white glue
  • green food coloring  (or red or your choice of color)
  • bowl
  • wooden spoon
  • timer

Pour glue into the bowl. Pour 1 cup of cornstarch into the glue. Stir the mixture for two minutes, using a spoon. Pour 3 cups of warm water and five drops of food coloring into the bowl. Stir the mixture for two minutes to combine the ingredients completely. Select any color of food coloring that you prefer.

Allow the mixture to sit undisturbed for five minutes to allow it to congeal. And voila! You have slime!Holiday slime as a gift

Roll it into a ball and knead it for one minute.  Roll it into a ball and drop it on a smooth surface. Watch what happens. As you shape it and work it more, it becomes more like putty, but it will always lose its shape over time.

Do not eat slime! Store the slime in a plastic bag.

What’s the science? Slime is a non-Newtonian fluid. Liquids that pour and behave like water and oil are called Newtonian fluids and obey Newton’s model of viscosity, which refers to a fluid’s resistance to flow. If a fluid is heated, it tends to become less viscous, and if a fluid is cooled, it tends to become more viscous.

Some liquids, however, do not obey Newton’s model of viscosity, because their viscosity can be affected by factors other than temperature. These fluids are called  non-Newtonian fluids, such as slime. According to “The Science of Slime,” produced by The American Chemical Society, non-Newtonian fluids have one of two basic behaviors:

  • Shear-thinning — a decrease in viscosity when a shear stress is applied
  • Shear-thickening —an increase in viscosity when a shear stress is applied.

Most types of slime are shear-thickening. For example, if you press water with your hand, the water will not offer much resistance; if you press slime, it becomes harder, or offers more resistance.

Most types of slime are also  examples of polymers. A polymer is made up of very large chains of molecules that are composed of repeating units known as monomers. What are some common polymers? Rubber, plastic and nylon. Starch is a natural polymer — it is a long chain of sugar molecules.

Enjoy! And if you’re feeling very creative, you can make Holiday Slime to give as gifts! (See photo.)