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<strong>WSKG</strong><br />
Science in the Park<br />
DIRECTIONS:<br />
1. Give each student a zip-lock bag, wooden stir stick, cup and assist them<br />
with the following steps:<br />
2. Have students measure 2 tsp of glue and 2 tsp of water into their cups.<br />
3. Stir glue/water mixture.<br />
4. Add Borax solution to glue/water mixture 5 drops at a time.<br />
5. Stir mixture. The mixture should start creating a visible polymer on the<br />
end of the stir stick. Continue adding Borax solution in small amounts until<br />
all liquid disappears in your cup. Do not add too much cross linker<br />
solution or the reaction will not work.<br />
6. Have students take the polymer out of the cup and touch it. They should<br />
roll the mixture around in their hands, first slowly and then quickly.<br />
7. Have students place the polymer on the table, what happens? It should<br />
ooze like a liquid. Have students pull the polymer apart and it will break<br />
apart like a solid.<br />
8. Store in Ziploc bag (which is also a polymer).<br />
RESULTS:<br />
The polymers in silly putty have covalent bonds within the molecules, but<br />
hydrogen bonds between the molecules. The hydrogen bonds are easily broken.<br />
When small amounts of stress are slowly applied to the putty, only a few bonds<br />
are broken and the putty "flows". When larger amounts of stress are applied<br />
quickly, there are many hydrogen bonds that break, causing the putty to break or<br />
tear. Examples of polymers are plastics, such as plastic bags, rubber, synthetic<br />
fabrics in some shirts and pants, keyboard and computer casings, Ipods, cell<br />
phone covers, glasses (including lenses if they are not glass)<br />
QUESTIONS:<br />
How can it be solid and liquid at the same time?<br />
Is a polymer more than one molecule? (hint: name the ingredients<br />
used for the experiment)<br />
Why isn’t your hand wet after you let the mixture slide through your<br />
fingers?<br />
**Important note! Do NOT pour Silly Putty down the drain<br />
It will<br />
clog the pipes. Dispose of the mixture in the zipper lock bag in the<br />
garbage!<br />
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