This was a fun experiment that didn't take much time and we had all the supplies inside our house. (No pre-planning, shopping necessary!) I did this with my 6-year-old, 4-year-old, and 3-year-old and they all loved it!
1) Sharpened pencils (the more the merrier!)
2) Large plastic bag
The idea is to find out what will happen if you press a sharp pencil into a bag full of water?
First, ask your kids what they think will happen.... then, let them try it out!
My kids loved this and were able to put all 14 of our pencils in without a drip of water coming out!
The science behind the experiment is that the plastic bags are made of polymers. Polymers are chains of molecules that are flexible, so they give the bag its stretchiness. When the pencil pokes the bag, the stretchy plastic hugs the pencil, creating a watertight seal. The bag doesn't leak!
Now, for the fun part.... pulling out the pencil! (This is why we did this outside, although this could be done over a sink!)
And you don't even have to ask, I'll tell you.... yes, we did this over and over and over again.