Needle Through a Balloon

Submitted by:Agnes Simon, Greenfield School; Gilbert, AZ
Endorsed by: These lesson plans are the result of the work of the teachers who have attended the Columbia Education Center's Summer Workshop. CEC is a consortium of teacher from 14 western states dedicated to improving the quality of education in the rural, western, United States, and particularly the quality of math and science Education. CEC uses Big Sky Telegraph as the hub of their telecommunications network that allows the participating teachers to stay in contact with their trainers and peers that they have met at the Workshops.
Date: May 1994

Grade Level: 4 - 6, Science

OVERVIEW:  This lesson can be utilized in a unit on
Chemistry specifically    when discussing various molecules.
One  kind of molecule is the polymer.  This demonstration
and/or hands-on activity  can allow children to experience
the polymer.

PURPOSE:  This activity is designed to help children
understand polymers and to experience the enjoyment of
Science.

OBJECTIVES:  Participants will be able to
1.  insert a needle through a balloon
2.  understand and explain polymers
3.  explain why the needle can be inserted through a
    balloon

RESOURCES/MATERIALS:
balloon
one of the following pointed objects:
     30-35cm (12-14) upholstery needle
     sharpened knitting needle
     bamboo skewer
     coat hanger wire sharpened to a point
a small amount of cooking oil
paper towel or cloth  (optional)

ACTIVITIES AND PROCEDURES:
Time:  Getting ready:  None
       Doing the activity:  15-20 minutes


Safety and Disposal:
For personal safety, store the needle with the point
inserted in a cork when not in use.  This also keeps the
needle point from becoming dull.

Procedure:
1.   Inflate the balloon and tie it off.  You might want to
     let a little air out of the balloon before tying it
     off, so it will be easier to puncture the balloon
     without breaking it.  Make sure the balloon is not
     longer than the needle.
2.   Dip the tip of the needle or  bamboo skewer into the
     cooking oil.  Alternatively, use a paper towel or cloth
     to spread the oil along the entire length of the
     needle.
3.   Using a gentle twisting motion, insert the needle into
     the nipple end of the balloon, the end opposite the
     knot, where the balloon is thicker.
4.   Continue pushing and twisting the needle until it
     emerges from the other side close to the tied end.  The
     balloon with not burst.
5.   Pull the needle out slowly through the tied end.  The
     balloon will slowly deflate.
6.   After the needle is out, jab the balloon sharply with
     the needle,  It will pop.
7.   Ask the students why the balloon did not pop when the
     needle went through it.  Tell them that the balloon is
     made of molecules (polymer chains) that stretch and
     seal around the needle.  When the balloon was jabbed
     the molecules did not have time to stretch and surround
     the needle.

TYING IT ALL TOGETHER:   This activity can be an
introductory activity or used as part of a series of lessons
on polymers.  Activities  that can be used before or after
the balloon  lesson   are the Rubber Band Stretch,
Superballs (made from glue and borax ), and Glop (made with
cornstarch and water).