Here's a fun experiment we tried in class today - it went so well that we are going to show it in assembly on Friday
What you need:
Plastic Zip Lock Bags
Sharp Pencils
Water
What to do:
Fill plastic bag with water and make sure to seal it tight.
Gently 'stab' a pencil through the palstic bag until it pierces through the other side.
Surprise, surprise, NO water leaks out!
The Science behind it:
Despite what it looks like, the zipper-lock bag isn't covered
in a magical sealant that blocks leaks. Well… not exactly. Plastic bags like
these are made out of our favourite kind of materials, polymers! Polymers are
long chains of individual molecules, called monomers. (See that? Mono = one.
Poly = many. Mers = molecules.) When you puncture these bags with a sharpened
pencil, you're essentially separating polymer chains without breaking them. The
long chains of molecules than squeeze in tight around the surface of the pencil
preventing any sort of leak. Polymers continue to prove an indispensable part
of life. - See more at: http://www.stevespanglerscience.com/lab/experiments/leak-proof-bag#sthash.jBCRn21H.dpuf
