Production Team Patrice Pages, Lead Editor Cornithia Harris, Art Director Therese Geraghty, Copy Editor
ACTIVITY
Administrative Team Marta Gmurczyk, Administrative Editor
By Erica K. Jacobsen
Technical Review Seth Brown, University of Notre Dame David Voss, Medina High School, Barker, NY
Education Division Mary Kirchhoff, Director Terri Taylor, Assistant Director, K–12 Science Policy Board Shelly Belleau, Chair, Thornton, CO Scott Goode, Columbia, SC Ethan Sullivan, Granada Hills, CA Kristine Lynn Rademacher-Gorovitz, Chandler, AZ Kathleen M. Cooper, Varnville, SC Steve Long, Rogers, AR ChemMatters (ISSN 0736–4687) is published four times per year (Oct/Nov, Dec/ Jan, Feb/March, and April/May) by the American Chemical Society at 1155 16th St., NW, Washington, DC 20036–4800. Periodicals postage paid at Washington, DC, and additional mailing offices. POSTMASTER: Send address changes to ChemMatters Magazine, ACS Office of Society Services, 1155 16th St., NW, Washington, DC 20036. Subscriber Information Prices in the United States, Canada, and Mexico: $16 per subscription. For more information, please contact ACS Member Services, P.O. Box 182426, Columbus, OH 432182426; tel.: 1-800-333-9511; fax: 1-614-4473671. Information is also available online at: www.acs.org/chemmatters. Professional writers wishing to write for ChemMatters can request the writers’ guidelines by sending an e-mail to: chemmatters@ acs.org. The American Chemical Society assumes no responsibility for the statements and opinions advanced by contributors. Views expressed are those of the authors and do not necessarily represent the official position of the American Chemical Society. The activities in ChemMatters are intended for high school students under the direct supervision of teachers. The American Chemical Society cannot be responsible for any accidents or injuries that may result from conducting the activities without proper supervision, from not specifically following directions, from ignoring the cautions contained in the text, or from not following standard safe laboratory practices. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, now known or later developed, including, but not limited to: electronic, mechanical, photocopying, recording, or otherwise, without prior permission from the copyright owner. Requests for permission should be directed in writing to:
[email protected].
Chemistry—How Sweet It Is! What is your favorite holiday? Do you look forward to a frightening Halloween? Dream about the over-indulgence of turkey and football at Thanksgiving? Cherish special time with your sweetheart on Valentine’s Day? What about a moment to celebrate chemistry? Grab your calendar and pencil in this year’s National Chemistry Week (NCW), which runs from October 19 to October 25. Many American Chemical Society (ACS) ChemClubs use NCW as an opportunity to share cool hands-on chemistry in their communities. It’s a fun way to highlight how chemistry contributes to our lives. Every year, ACS picks a new NCW theme. You won’t want to miss this year’s candy theme “The Sweet Side of Chemistry.” Here is one activity to get you started.
Gobstopper Explorations Materials
• Three Gobstopper
jawbreaker candies, in three different colors
• 250-mL clear, color-
less beaker or similar container
• Tap water • Paper clip
Safety: Candies that have been in a laboratory environment or used with laboratory equipment should not be eaten. Instructions 1. Add 100–125 mL tap water to a 250-mL clear, colorless beaker. 2. Gently place two Gobstopper candies of two different colors in the beaker. They should sit across from each other, touching opposite sides of the beaker.
3. Allow the outer coating of the Gobstoppers to dissolve in the water for about 5 minutes. What do you see? Be sure to view it from the top and from the side.
4. Bend a paper clip to form a wire loop with a handle. The wire loop needs to be shaped so that it can hold the third Gobstopper candy.
5. Place the third Gobstopper candy in the wire loop. Hold onto the wire handle and suspend the candy in the water in the center of the beaker. The candy should be held just below the surface of the water.
6. Allow the outer coating of the third Gobstopper to dissolve in the water. What happened?
What are possible explanations for why this happened? The reasons are not clear at this point, and other scientists are experimenting, too. What further experiments could you do to learn more about why Gobstopper candies acted like they did? Would the effect be the same with other candies?
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A student at Tarpon Springs High School, Fla., makes a batch of gummy colloids.
ChemClubs
and Growing!
Experience chemistry beyond the classroom—start an ACS ChemClub at your school! It is free to join, and you will receive useful resources, such as demos, experiments, and science swag. Find out more at: www.acs.org/chemclub. Join today at: http://fs7.formsite.com/ACSEducation/Chemclubapp/index.html
www.acs.org/chemmatters
Tarpon Springs High School, Tarpon Springs, Fla.
Teacher’s Guide William Bleam, Editor Donald McKinney, Editor Ronald Tempest, Editor Susan Cooper, Content Reading Consultant David Olney, Puzzle Contributor
