Hooked on Science: Leak-proof bag

Here's a cool science trick that might get you and the entire family "Hooked on Science."

Materials

• Several round pencils
• 1 plastic zip-top bag
• Water

Instructions

STEP 1: Fill a plastic zip-top bag about three quarters of the way with water.

STEP 2: Stick a sharp round pencil through the bag.

Explanation

The bag is made of polymers. Polymers are long chains of molecules and when the sharp pencil is pushed through the bag these molecules seal up around the pencil, which prevents the water from gushing out of the bag.

Jason Lindsey is a Science Outreach Educator with Hooked on Science. Check out his website "Hooked On Science" at hookedonscience.org for webcasts and experiments that might get you hooked on science. Send him your science questions at jlindsey@hookedonscience.org. More science experiments can be found at www.semissourian.com.