Summary

In this lab, students will follow the procedure for creating a polymer, flubber, which will be similar in consistency to Silly Putty. Students will then design an experiment to test a physical property of the flubber that they have created using the scientific method.

Grade Level

Elementary and middle school

NGSS Alignment

This lab will help prepare your students to meet the performance expectations in the following standards:

• MS-ETS1-2: Evaluate competing design solutions using a systematic process to determine how well the meet the criteria and constraints of the problem.
• 2-PS1-1: Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.
• 3-5-ETS1-3: Plan and carry out fair tests to which the variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
• K-2-ETS1-3: Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs.

Objectives

By the end of this lab, students should be able to

• Understand what makes a substance a polymer.
• Identify various examples of physical properties.
• Design a controlled experiment, following the outline of the scientific method.

Chemistry Topics

This lab supports students’ understanding of

• Polymers
• Mixtures
• Physical Properties
• Experimental Design
• Scientific Method

Time

Teacher Preparation: 20 minutes
Lesson: 1-1.5 hours

Materials

Per lab group to create flubber

• Mixture A:
  • Plastic Cup or bowl
  • ¼ or 60ml cup warm water
  • 1/3 cup or 80ml of white glue (almost an entire standard bottle)
    
  • 1-2 drop of food coloring
    
  • Plastic Spoon
    
• Mixture B:
  • Plastic Cup or bowl
  • 1 teaspoon or 5ml of Borax Powder
  • 3 tablespoons or 40ml of warm water
  • Plastic spoon
  • 1 Ziploc® bag for storage
    
• Optional (for experimental design portion):
  • Rulers, meter sticks, tape measures
  • Freezer or ice
  • Stop watch/timer
  • Electronic scale

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.
• Do not allow students to heat the flubber, it will quickly become very sticky, like glue and will burn the skin when touched.

Teacher Notes

• Students should be placed in pairs for this lab.
• The amount of flubber produced from following the procedures should be plenty to use for each lab pair. The flubber can even be separated into equal pieces so students can conduct multiple trials for comparison.
• When making the flubber it is very important that the borax solution be added slowly, and stirred frequently. It should not all be added to the glue mixture at one time.
• The flubber should not be sticky when it is completed, it just be easy to form it into a ball, break it into pieces, etc. The food coloring will not stain once the flubber is completed.
• The stages of flubber creation are shown in the photo series below:

• Students may need encouragement as they plan for their experiment, some easy ideas include:
  • Will temperature effect the number of times a flubber ball bounces? (note, do not allow students to heat the flubber, only cool it)
  • Will the size of a flubber ball effect the height of its bounce?
  • Will the temperature of flubber effect how long it can hold its original shape? (note, do not allow students to heat the flubber, only cool it)
• When students create a hypothesis, encourage them to use the structure: If… then… because…. This requires students to make a prediction, but also pushes them to justify their thoughts with a reason for their prediction.