Pencil Trick with Baggie
Everyone loves this cool pencil trick! I did this for over 20 classes in one week….and every single class enjoyed making predictions and participating in this experiment. Yes it is an experiment but we all love a cool trick.
You will need:
Several very sharp pencils~they do need to be sharp to separate the polymers in the baggie. This is essential to the success of the pencil trick.
Water~you need to fill the baggie over half full
An assistant! I often have a student hold the baggie. It needs to be someone that will not drop the bag. You will know who can do the job in your group.
How to make it happen:
Get your assistant to hold the baggie. I suggest a two handed pinch at the top of the baggie. For the first round you are the pencil pusher. Simply push the pencil through the baggie all the way. Leave the pencil in place. (if you don’t you will have a water spout….and no one will be impressed…you will also have a mess to clean up) Anyway you get the picture.
You can continue to push pencils through the baggie. I have put quite a few in a quart size baggie. By that I mean 12! You can put pencils through both sides of the baggie. If you have the students put pencils through the baggie make sure they push the pencil through both sides and not all the way through.
How it works:
The baggie is made of polymers that stretch and separate just enough to allow the pencils to pass through. It reminds me of putting a pencil through a sweater. The strands of yarn are pushed aside but the weave of the sweater hugs the pencil. These polymers behave in the same way. The polymers are permanently separated that is why the water will pour out if the pencils are pushed through. If you want to see what happens please stand over a sink!
I like to walk around school with the baggie full of pencils….hey don’t judge teachers need cool factor. You know they do! This also makes you very cool at picnics and Bar-B-Ques etc. I know this.
If you would like to see me show how to do this experiment follow me on Instagram at Science is for Kids. Please click here and check me out.
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