Experiment While Making a Bouncy Ball
This activity demonstrates an interesting chemical reaction,
primarily between the borax and the glue. The borax acts as a
“cross-linker” to the polymer molecules in the glue – basically it
creates chains of molecules that stay together when you pick
them up. The cornstarch helps to bind the molecules together so
that they hold their shape better.
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Controlled experiment - an experiment where only one
variable is changed. The rest remained unchanged.
Independent variable – the variable that is deliberately
changed.
Dependent variable – the variable that changes in
response to the independent variable.
Experimental group - the group in an experiment that
receives the variable being tested
Control group – exposed to the same conditions as the
experimental group, except for the one independent
variable you are testing.
Quantitative data - numbers that are obtained by counting or measuring. Ex: height or weight.
Qualitative data – descriptive and involve characteristics that cannot usually be counted. Ex: color or
smell.
Materials:
 Borax
 warm water
 corn starch
 glue
 2 small mixing cups
 a plastic spoon
Procedure:
1. Label one cup ‘Borax Solution’ and the other cup ‘Ball Mixture’.
2. Pour 4 ounces (120ml) of warm water into the cup labeled ‘Borax Solution’ and 1 teaspoon of the borax
powder into the cup. Stir the mixture to dissolve the borax.
3. Pour 1 tablespoon of glue into the cup labeled ‘Ball Mixture’. Add 3-4 drops of food coloring, if desired.
4. Add 1/2 teaspoon of the borax solution you just made and 1 tablespoon of cornstarch to the glue. Do not
stir.
5. Allow the ingredients to interact on their own for 10-15 seconds and then stir them together to fully mix.
6. Once the mixture becomes impossible to stir, take it out of the cup and start molding the ball with your
hands. The ball will start out sticky and messy, but will solidify as you knead it. Once the ball is less
sticky, continue rolling between your hands until it is smooth and round!
Now that you have created a ball using the instructions. Pick a part of the experiment and double it. (Ex: 1
tablespoon make it 2 tablespoons.)
Report: (1-2 Pages typed. Font: Times New Roman. Size 12.)
1. Title – Create a title of your investigation, your name, you class period and the date
a. Example – Double Glue in a Bouncy Ball.
2. Hypothesis - this should be a clear statement that describes what variables your experiment is going to
evaluate.
a. Example: If you increase the amount of glue used, then the ball you create should bounce higher.
3. Listed materials
4. Method - The step-by-step method for performing the experiment and collecting data.
5. Results – Compare and contrast the new ball versus the original ball you made earlier.
6. Review - Complete the following:
a. Discuss your thoughts on the lab. Did you enjoy it? What did you learn?
b. Review your hypothesis - is the hypothesis supported? If not, why?
c. Evaluate your method - What would you do differently if you did the experiment again?
7. Analysis:
a. Define the control group in this experiment.
b. Define the experimental group in this experiment.
c. Define the independent variable in your experiment.
d. Define the dependent variable in your experiment.
e. Provide an example of qualitative data in this experiment.
f. Provide an example of quantitative data in this experiment.