Do this fun “magic trick” for all of your friends! All you need is a plastic bag, water, and some pencils!
Materials:
Sharpened pencils, a Ziploc bag, water
Time Estimated:
5 minutes
Directions:
Fill the bag one half full of water and then seal.
Time for teamwork! Have one person hold the bag and have the other push the pencil through. Watch as the bag keeps all of the water inside!
Pro Tip: Be careful not to push the pencil all the way through or the water will spill out.
Think Like a Scientist:
What if you use a different type of bag? Do you think a paper bag would work? Why or why not? Let us know what you find in the comments!
What if you use a different type of pencil or pen? You might find that a smooth, round pencil works differently than a hexagon shaped pencil! Try it out and let us know in the comments what you discover!
How It Works:
The Ziploc bag is made of a material called polyethylene. The molecules of polyethylene are super flexible so they can create just enough space for the pencil to push through! At the same time, they can quickly form a temporary seal against the edge of the pencil! That way, the pencil can go in, but no water leaks out.
However, once you pull the pencil out the hole will still remain in the plastic! Oh no! This is because the plastic molecules have been pushed too far from each other to reconnect.
Materials scientists study the properties of different materials, like Ziploc bags, and help figure out the best way to design new products!
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
