Oobleck - What State's the Matter

Sharon Jensen, RTR High School, Tyler, MN; Probe: Uncovering Student Ideas In Science,
by: Page Keeley, Francis Eberle, and Chad Dorsey (NSTA Press) 

Summary

Students will investigate what constitutes a solid and a liquid state of matter. Using the probe, students' misconceptions on states of matter will be exposed. The lab, which uses a cornstarch, water and food coloring mixture, will be explored. The students will determine how that exploration will take place and devise a procedure to determine the state of matter. Students will then, as a group, present their findings to the class. After all the groups have presented their findings, the groups with the same findings will combine and defend their findings to the other group(s) until the class, as a whole, has reached a consensus. 

Learning Goals

Students will use critical thinking, data analysis, quantifying and communication skills. Through the whole process the students will generate a basic definition of the states of matter and through those definitions they will further their understanding of states of matter.

Context for Use

This is mainly a lab exploration that will take approximately three 50 minute periods. One day will be for the probe which will expose misconceptions, the pre-lab and the designing of the lab procedure. The second day will be the actual lab procedure and data taking. The third and final day will be the presentations and class "defense" of findings. This high school lab has minimal safety concerns and the set-up is quick and easy. Prior to this lab the students will have had practiced designing and doing their own lab procedure based on the given task. Also prior to this lab, the students will have practiced observation skills and collecting data into forms that are easy to understand at a glance. This activity will occur in the chemistry portion of physical science. This lab can easily be done in a variety of settings and the biggest draw-back is the mess that can, and often does occur.

Subject: Chemistry:General Chemistry, Physical Science
Resource Type: Activities:Classroom Activity, Lab Activity
Grade Level: Middle (6-8), High School (9-12)

Description and Teaching Materials

 Have students discuss the properties of solids, liquids, and gases that you have studied in class.  Then, let students know that today they will need to determine if a special substance "Oobleck" is a solid or a liquid.  Many students have already become familiar with this substance and will exclaim that it is a Non-Newtonian fluid.  However, I emphasize to them that there is no right or wrong answer.  Instead, I am interested in how they interpret their experimental findings to explain the conclusion that they come to. Pass out a small container of Oobleck (see attached) to each student group and give them 5 minutes to observe.  You can hit a container of oobleck with a hammer or a mallet- this always gets a good response from the kids and it gives them a chance to see a dramatic example of one of oobleck's behaviors. Then pose the question, "How can you determine what state of matter Oobleck is?"   The students will determine the procedure they will follow on the second day, what data they will collect, and how they will present that information to the rest of the class. On day two, the student groups will follow their procedure. On the third day, each group will present their findings to the class, and then groups with similar findings will defend their findings. By the end of the period, the groups should reach some basic agreements on concepts. An alternative way to assess, rather than a group consensus is to have students work in groups or individually to write a claim, evidence, reasoning paragraph (CER) to explain what state of matter they think Oobleck is and to explain their claim using evidence from their experimentation.

Teaching Notes and Tips

For a group of 24 students, a full container of cornstarch will be needed. Any food coloring will work but I prefer the darker colors. An ice cream bucket works well for mixing. You may need to mix with your hands to get a good consistency and that consistency will loose moisture if it is not covered. You can add more water to it - or less water depending on which state of matter you want them to target.

Recipe for Oobleck:

 1.5 cups corn starch

1 cup water- add any desired food coloring to the water first- this will make mixing it much easier!

 Make sure the surface is clean to start and then the Oobleck can go back in the ice cream bucket and can be used over several times. Clean-up is easy with water and a large bath towel! 

Assessment

Make a copy of the CER template by following the link here: 

CER Template Link

____________________________________________________________________________________________________________________________

Oobleck CER

Instructions:

Write your Oobleck CER as one complete paragraph here.  

Highlight the Claim in Red- A statement that answers the original question.

Highlight the Evidence in Green- Scientific data that supports your claim. In this case, your evidence will come from your lab results.

 Highlight the Reasoning in Blue.- An explanation of WHY the evidence supports your claim.  

You should include any relevant scientific principles.  In   

this case, it will be important to discuss the characteristics 

of a solid or a liquid to help explain why YOUR data 

supports your claim.

Extension

Have students brainstorm possible ways engineers could use Oobleck.  

Download an editable document at the link below

Link to engineering extension

_____________________________________________________________________________________________________________________________

Brainstorm:

What are three ideas for how this substance (one one like it) could be used?

1)

2)

3) 

Make an Invention: 

Choose one of your ideas above. Using words, describe your invention, how it could be used, and why it would be helpful.

Draw and label a picture of your invention in action.

Downloads

References and Resources