Educating Risa

This afternoon the boys and I attended another Mad Science workshop organized by a homeschooling Mom, as we so enjoyed the one on dry ice and the states of matter a few months back. This time the topic was polymers. Here’s the pictorial diary of events (hover mouse over pics for details):

The instructor began the class by talking about molecules, and explained that polymers were made of molecules that liked to stick together in really long chains, thousands and thousands or molecules linked together. She contrasted that with water, and got some volunteers to be H20:

She then handed out a polymer to each child (silly putty type), encouraging them to explore it to investigate the properties of polymers. We had kids stretching, shaping, breaking (when you pull too quickly), twirling, etc. their polymers:

Daegan discovered one other property: it bounces! And quite erratically if you haven’t shaped it into a neat ball:

The instructor then handed out a different sort of polymer: a light-weight “packing peanut” (styrofoam chip). She again asked the kids to investigate its properties: does it stretch? bounce? can it be shaped?

After collecting all the styrofoam bits, she filled a beaker with the packing peanuts and added a small amount of liquid (acetone), and swirled:

This showed the kids that this ‘packing peanut’ polymer is indeed similar to the silly-putty type polymer: it just has a whole lot of air inside (which is why it is so light). But if you scrape up what remains at the bottom of the beaker (the packing peanuts were almost all air!), you’ll find that same stretchy silly putty type polymer:

The next demonstration required a volunteer, and Daegan got to participate. She began by holding a clear plastic bag filled with water and a sharp pencil over his head. He was pretty nervous! And then…poke!

But the plastic bag, being a somewhat flexible polymer, formed a seal around the pencil, and nothing leaked! Daegan had to look for himself:

Now what would happen if we changed the flexible plastic bag to a more rigid polymer? She held a water-filled styrofoam cup above his head, and…poke!

This time, as the polymer was not flexible, it did not form a seal, and the water leaked:

And Daegan can now say he has joined the ranks of scientists everywhere, sacrificing himself in the name of science. Or at least getting his shirt wet.

The instructor added acetone to the stryfoam cup (once empty!), showing us the lattice structure of air pockets:

The next demonstration was similar to the bag of water, and involved a vaseline-covered (polymer-covered) skewer and a balloon. That certainly held the kids’ attention:

It took three tries (giving me the opportunity to whisper in Daegan’s ear: “If at first you don’t succeed, try, try again”), but she did get it to work:

 

Lastly, each kid got to make their own slime polymer, choosing the colour by combining (or not) primary-coloured paint:

And presto! Oopy, goopy, slimy polymer:

Some kids made slime that would be fun for practical jokes. Ah–chooooo!

And some kids gave real meaning to the phrase, “hands-on science”!

Overall, the boys enjoyed this presentation. I thought it was not quite as “flashy” or “whiz-bang” as the previous mad science presentation, which they agreed with, but Daegan pointed out that this one was much more hands-on. And, he added, “I do best when I get to touch stuff.” Thanks again to homeschooling Mom Sandra for setting this up!