This leak proof bag experiment is a fun science experiment in which your kids get to poke pencils right through a plastic baggy filled with water.
- Sharpened Pencil
- Zip-up Bag
- Fill a zip-up bag about ½ way with water and sealed up.
- Quickly stab a sharpened pencil through the zip-up bag.
- Try stabbing multiple pencils through the zip-up bag.
Plastic bags are made from polymers (long chains of molecules) that are flexible. When you stab a pencil through the bag, the polymers move apart but then the flexibility of the polymers push back toward the pencil and form a temporary seal. This prevents the water from leaking out the holes.