Fun Recipe and Science with Bartholomew and the Ooblecks
1 ½ cups of corn starch
1 cup water
Food color - if desired
Slowly stir the water into the cornstarch until it is the consistency of pancake batter. Add food color if desired, keeping in mind some food coloring will stain clothing and skin. Store the Oobleck in an airtight container.
¾ cups warm water
1 cup Elmers glue
Food coloring – if desired
2 teaspoons Borax
½ cup warm water
2 mixing bowls
Stir the ¾ cup warm water into the Elmers glue. Add food coloring as desired. In a separate container mix the Borax with ½ cup of warm water. Pour the glue mixture into the borax mixture. Reach into the bowl and knead the substance together for about 2 minutes.
Oobleck & Flubber can be used to teach students about states of matter and how appearances can be deceiving. Students should understand the basic states of matter, solid, liquid and gas. Water can be used to demonstrate these states easily by freezing it or boiling it to demonstrate ice and steam. Discuss some of the characteristics of solids and liquids. Make a list of these characteristics where students can review it throughout the lesson. Use the following activity to help students understand that some substances that may appear to be solids are actually liquids.
Divide the students into small groups and give each group a recipe to follow, either for Oobleck or for Flubber. Have the students make the recipe and then decide if it is a solid or a liquid. Provide each group with a small pitcher, a piece of craft wire, a small plastic glass and an open area of floor. Give each group a piece of paper with the following questions:
- What happens when I put it into the pitcher?
- Can I form a baseball shape? What happens if I slap the baseball with my hand? What happens to that shape if I set it on a desk?
- What happens to the baseball shape if I drop it on the ground?
- Can I cut through the baseball shape with the wire? What happens?
- If I put the ‘stuff’ into the glass, turn the glass over on top of a desk and take the glass off, what happens to the ‘stuff’?
Students should predict what they think will happen for each experiment before they perform it.
The students should be given enough time to perform these simple experiments and record their observations. Once all of the observations have been made bring the class back together to discuss them. The following should be the observations made for Oobleck and Flubber:
- The Oobleck should relax in the pitcher and cover the bottom, no matter how it was put into the pitcher. The Flubber will remain in the shape it was in when the students put it into the pitcher.
- Both can be used to form a baseball shape. Both will retain their shape when slapped. The Oobleck will flatten as soon as it is placed on a hard surface. The Flubber will maintain its shape.
- The Flubber will bounce and the Oobleck will not.
- Both can be cut with a wire.
- The Oobleck will lose its shape immediately and the Flubber will maintain its shape.
If enough is made you can have the students who made Oobleck combine theirs into a shallow baking dish and roll a marble across the top. The marble should not sink into the the Oobleck.
Conclusion and Additional Informaion
Both substances appear to be solids, however Oobleck is actually still a liquid. Another substance that appears to be solid, but is a liquid is glass. Glass windows that have been in place for many years are thicker at the bottom than at the top. Students can put their Flubber or Oobleck into plastic bags to take home.