Hey Science Fans!
Here’s a couple of great activities that you can do at home to amaze your friends and family (and explore learning with your kids!)
Instructions
ZIPLOC BAG DEMONSTRATION
Here’s what you’ll need:
Ziploc Bag
Water
2 Sharp Pencils
Fill the Ziploc bag with water and seal it. Poke the pencils through the bag, being careful not to tear the bag.
What’s happening?
The polymers in the bag (in this case polyethylene) are flexible enough to allow the pencils to pass in between the molecules. Because they are slightly stretchy, they fill any gaps between the pencil and the bag, keeping leaks to a minimum.
Experiment!
What happens if you use something really thin, or really thick instead of a pencil?
Further Reading:
https://www.stevespanglerscience.com/lab/experiments/leak-proof-bag/
BALLOON DEMONSTRATION
Here’s what you’ll need:
Latex Balloon
Toothpick
Deep breaths
Inflate the balloon about halfway so that it has a nice round shape, but isn’t completely full. Tie it off so that it doesn’t leak. Insert the toothpick in either the base of the balloon, or near the top of the balloon.
What’s happening?
The polymers in the balloon (in this case latex), are very stretchy AND thicker near the base and top of the balloon. Because the balloon isn’t fully inflated and the balloon is thicker near these points, the polymers can still stretch to fill the space created by the toothpick. The balloon pops if you stick it on the side because the balloon is thinner there and the polymers are stretched further apart.
Experiment!
Using a wooden skewer, try to pierce both the bottom AND top of the balloon at the same time.
How big can you inflate the balloon before it pops when you try the demo?
Further reading:
https://www.stevespanglerscience.com/lab/experiments/skewer-through-balloon/