Name ______Date ______Period ____ # ____

Gak Lab

1. PROBLEM: What is the correct amount and sequence of materials in order to make Gak with a silly putty consistency?

2. RESEARCH: Periods in history are often described in terms of the specific materials that were used to make important objects in that era (i.e. Stone Age, Iron Age, etc.). The 20th century has been named the “Polymer Age”. Many of today’s objects are made of materials such as nylon, plastics, celluloids, and polyvinyl chlorides.

Polymers are very large molecules made of repeating units. Small units, called monomers, are joined together by covalent bonds to make long chains. Physical properties of polymers are determined by how much “cross-linking” exists between the long chains. This is very similar to the steps on a ladder, sometimes they are very close together and other ladders have wide-spread gaps between steps.

Solutions of polyvinyl acetate, like white glue, can be made into polymers called gels by the addition of a borax solution. Borax cross-links the polymer chains to form the Gak gel. This is a 3-dimensional network. The gel traps the water molecules and has fascinating properties when handled, poured, stirred, or stretched.

3. HYPOTHESIS: If we add ______, then we will be able to make Gak and have a product with a silly putty type of consistency.

4. EXPERIMENTALDESIGN: **Please use no more than 20 mL of any material because supplies are limited.

Materials- The materials used were ______.

Procedure(List the sequence and amounts of materials that you used for each trial in this table.)

Trial / Amount of Borax solution added (mL) and which step (1st, 2nd, or 3rd) / Amount of glue added (mL) and which step (1st, 2nd, or 3rd) / Amount of water added (mL) and which step (1st, 2nd, or 3rd)
1
2
3

5. DATA/OBSERVATIONS: These are the results of the experiment, presented in one or more of the following formats: tables, graphs, or drawings.

Trial Number / Observations (What did the Gak feel like and did it have the right consistency?)
1
2
3

6. CONCLUSION:

Write your conclusion paragraph in the space provided. (Remember to address whether your initial hypothesis was supported or refuted. You should also use your data to explain why it was or was not supported.)

7. REPEAT AND/OR REDESIGN THE EXPERIMENT

What were some of the problems your group had and what you could do next time to prevent these problems?