Leak Proof Bag

Leak Proof Bag Science Experiment

To begin, fill a gallon size storage bag about half full with water. Then poke a pencil straight through the bag – in one side and out the other.

Much to everyone’s surprise, the bag won’t leak! This is because the bag is made of a polymer – which is long, flexible chains of molecules. When you poke the pencil through the bag, the molecules spread apart and then seal themselves around the pencil. It’s really cool!

My kids would do this for a long time if we had enough pencils. They just think it’s so cool that they can poke the pencils through the bag and it won’t leak.

If you are wondering what age this experiment is for, I will say that my 3.5 year old was able to do it no problem and as you can see she really enjoyed it. As always, supervision is required though.

Materials

• Gallon size storage bag
• Sharpened pencils
• Water

Steps

1. Fill a gallon size storage bag about half full with water.
2. Poke a pencil straight through the bag – in one side and out the other.