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Nancy Mosher Infant Jesus of Prague School
1101 Douglas Ave.
Flossmoor IL 60422
Eighth grade students will be able to complete a performance assessment
demonstrating their knowledge of polymers by:
1. Determining the properties/characteristics of polymers.
2. Discussing the relationships between types and uses of polymers.
3. Describing the molecular structure of polymers.
Each group of two to four students will need the following material:
Ziplock sandwich bag sharpened round pencil balloon
wooden skewer quart size Ziplock bag white glue
2 stirring rods liquid starch paper towels
2 small plastic cups 5 or 6 plastic or rubber objects per grade
5 or 6 non-polymer objects per grade
20 ml of 4% Polyvinyl Alcohol Solution (PVA)
3 ml of 4% Sodium Borate Solution (Borax)
1. Blow up a rubber balloon about half-way. Do not make the balloon taut.
2. Place a little cooking oil on the tip of a sharpened skewer and push it
completely through the balloon from where the balloon is tied to the nipple,
without popping the balloon.
3. Discuss with the class what they think is happening and why.
4. Fill a Ziplock plastic bag 3/4 with water. Push a sharpened pencil
completely through the bag.
5. Once again ask, "Why do you think the bag does not leak?" "Is there a
similarity between this and what happened to the balloon?"
6. Give each group a bag of water and have them push pencils through the bags.
7. Have the class compare what happens to the bag with what happened to the
balloon. Ask them to discuss the similar properties of the balloon and the
bag. See if they can think of any other substances that have these
properties. Have them hypothesize what they think is happening in both
1. Give each group a plastic bag filled with 6 items that are polymers and 6
items that are not.
2. Each group will sort the objects into two categories: Polymers or plastics
and non-polymers or non-plastics.
3. Have various groups compare their classifications and come up with some
agreement about the classification of each item.
4. Together discuss how each item was sorted and what characteristics or
properties they used to sort the items.
5. Together list the characteristics that are common to the plastic/polymer
1. Have each group brainstorm polymers and come up with as many items as
possible that are made up of polymers.
2. Have the groups discuss the relationship between the characteristic
properties of the items and their uses.
1. Discuss with the class what the term polymer means.
2. Give background about molecular structure of polymers.
3. Discuss synthetic vs. non-synthetic polymers.
4. Have each group link hands to represent a polymer chain.
5. Have one group become crosslinks and bond the polymer chain together.
1. Make a crosslinked polymer - silly putty.
2. Mix 2 tablespoons of white glue with 3 tablespoons of liquid starch.
3. Stir and work glue into mixture.
4. Form the polymer into a ball and rinse under water.
5. Squeeze the polymer while rinsing.
6. Examine its properties.
7. Discuss why it is a polymer and what makes it a crosslinking polymer.
Activity VI: PERFORMANCE ASSESSMENT
Have each student complete the following performance assessment to prove
that they understand polymers and their molecular structure.
In your secret laboratory, hidden away in the Andes Mountains, you finally
make the most important discovery of your scientific career. You make a
remarkable crosslinking polymer. You carefully perform the following steps:
1. Pour 10 ml of 4% Polyvinyl Alcohol Solution (PVA) into a small cup.
2. Measure 1.5 ml of 4% Sodium Borate Solution (Borax).
3. Add the Sodium Borate to the PVA and stir.
4. Remove the gel and knead it.
While kneading the gel, you slowly, and scientifically examine the substance and
study its properties.
You decide to sell the formula to the International Polymer Company that
happens to have a branch office across the valley from your secret lab.
In order to sell this new product you must do the following:
1. Prove that your substance is a crosslinking polymer.
2. Prove that your substance's properties are "new and improved." What
makes your polymer better than any other. (Be sure to do this as
scientifically as possible and be sure you have enough data to support
3. Show the molecular structure of your substance. Prove that your
substance is better than any similar non-polymer by being as graphic as
4. Finally, based on its properties, what creative new uses does your
substance have? What can the International Polymer Company do with
your new polymer based on its remarkable properties.
REMEMBER! ! ! To really sell your product, you must be clear, exact,
scientific and organized. Good Luck!
Assessment will be based on a rubric with points ranging from a score of 0,
not attempted, to a score of 6, exemplary response. The exemplary response
should contain the following information:
Gives a clear, coherent and elegant explanation of:
- numerical data using scientific measurement
- a chart, graph or table
- a list of at least 5 characteristics
- a comparison of this gel with other polymers
- an explanation and diagram showing molecular structure and crosslinking
- proper use of at least 5 new vocabulary words
- creative uses for each property of this new gel (slime)
Physical Science. 1991. D.C. Heath Company, p.499-505.
"Plastics", Wonder Science. Volume 5, Number 5, December 1991, American Chemical
Society/American Institute of Physics.