Glurch Meets Oobleck

Glurch Meets Oobleck

Glurch Meets Oobleck




Science Process Skills

* observing
* communicating
* comparing and measuring



Glurch Materials

* resealable quart size plastic bags
* measuring spoons
* 45 ml liquid laundry starch
* 25 ml liquid white glue
* 1/4 tsp. salt

To prepare:

1. Pour the starch into a baggie. Add salt and mix until it is completely dissolved.
2. Add the white glue.
3. Squeeze out the excess starch until the substance becomes doughy.
4. Knead. If the glurch is runny, add a few more grains of salt.



Oobleck Materials

* resealable quart size plastic bags
* measuring spoons
* 1 Tbs + 1 tsp water
* 2 Tbs corn starch
* 2 drops food coloring (optional)

To prepare:

1. Open your plastic bag and add 1 tablespoon of water.
2. Measure 2 tablespoons of corn starch and add to the water in the plastic bag. If you would like, add two drops of food coloring to the bag before sealing the bag.
3. Seal the plastic bag and mix the corn starch and water. Try shaking and kneading the plastic bag.





Doing the Activity

1. Look at the substances in your bags and make some observations about them. What do you see? What does it look like?
2. Open the top of each bag and touch the substances. What do they feel like? Does either one feel like anything that you have touched before?



Reflecting

* If both substances were poured, which would fill a container faster?
* Which substance would make a better substitute for thumbtacks?
* Which substance would be better measured in milligrams than milliliters?
* Which substance would make less noise when pulled up from a surface?
* Which substance would make a better emergency soccer ball?



Applying
What uses do you think could be for this substance? What would you name this substance?



What's Happening
Some materials don't quite fit our normal notions of solid, liquid, and gas. A suspension such as Oobleck is one. It behaves like a liquid in some ways, but it also has properties of a solid. Silly putty, quick sand, and glass are some other examples of strange substances. The molecular bonds are stronger than in a normal liquid, but not as strong as in a solid.



More Challenges

* Read the story "Bartholomew and Oobleck" by Dr. Suess.
* Create a Glurch and Oobleck Olympics. Make up a series of tests that can be tried with Oobleck and Glurch such as which one hides more easily in your hand.
* Create an invention that uses Glurch or Oobleck.



Activity Source
Fizz, Bubble, and Goo, Iowa State University Extension- Science, Engineering and Technology Youth Initiative, 32 Curtiss Hall, Ames, IA, 50011 (not for sale).