I’ve been having a lot of fun doing science experiments with my preschoolers over Zoom. Part of the reason why is because unlike in the classroom where we do one experiment while a few children help and others watch, on Zoom calls they each have their own supplies and a parent to help them with the experiment. My co-teacher and I have been trying our best to do experiments with items that can easily be found in everyone’s homes, that way no one has to go out to get supplies. Today’s experiment was super simple and fun. Before starting, have the children can make a hypothesis about what they think would happen if they poked a hole with a pencil through a bag full of water.
-Plastic sealable bag
Gather all the supplies. Make sure the pencils are sharpened to a point.
Fill the bag between ½ and ¾-full with water.
Seal the bag shut.
Holding the bag in one hand, use the other hand to slowly, but firmly, push one of the sharpened pencils through one side of the bag. You don’t need to be especially fast, slowly and carefully works well.
Repeat with the other sharpened pencils.
The science behind this experiment: Flexible plastic is made of polymer chains. The polymers have many molecules inside of them. When the pencil goes through the bag, the molecules in the polymer chains surround the pencil, sealing it up tightly and preventing leaks. But when you remove the pencil, the molecules don’t move to seal the hole, allowing the water to escape.