December, 2009
Total Page:16
File Type:pdf, Size:1020Kb
® DEMYSTIFYING EVERYDAY CHEMISTRY DECEMBER 2009 Hollywood’s Special Effects Chemistry Behind the Scenes, p.5 Space Food: Dining 220 Miles Above the Earth, p.11 QUESTION FROM THE CLASSROOM By Bob Becker k C A classmate recently reported on the element selenium. And then there are the ele- to bond carbon molecules into o IST He said that selenium is an essential mineral in our diets ments hydrogen and oxygen. long chains known as proteins. M ro Q F and that humans and other animals could not exist without it. Then, They seem to be indispensable So, it is reasonable to assume another classmate reported on the element manganese with a similar to life. Not just life as we know it, that a “nitrogen-less” universe ELEMENTS result. I had never even heard of these two elements. So I was think- but life of any kind. Not only do would also be a lifeless universe. ALL ing, what would life be like here on Earth without these elements? they play critical roles in adding How about selenium and to the complexity of carbon- manganese (mentioned in the If you consider all of But what if copper—or either based molecules, but they also question)? Trace amounts of A the elements that life selenium or manganese—had combine to make the most selenium are essential for the depends upon, you may come never been here to begin with? unusual compound—water. production of enzymes that are to the conclusion that we are Could life still have evolved? Liquid water is vital both as found in cells. Selenium defi- very lucky to be here at all. The For most of the elements listed a solvent—in which many of the ciency can lead to diseases, such human body contains roughly 40 below, I think the answer would body’s chemicals dissolve—and as thyroid disorders, psoriasis (a different elements. For other ani- be yes. If these elements had as an essential part of metabolic skin condition), and susceptibil- mals and plants, the list is very not existed, animals and plants processes within the body. ity to heart disease similar. But it’s easy to assume would have evolved to take No other liquid is and viral infections. that if any of these elements were advantage of the elements that known to do it Manganese plays a missing from our universe, sud- were available to them. as well. Water role in the liver, kid- denly our planet would become a There are a few elements that is—as far as neys, and the brain. lifeless wasteland. probably are critical to life. The we know—the In experimental If, right now, all of the first is carbon. Carbon atoms are only liquid that animals, manganese manganese and very good at bonding to one makes life pos- deficiency causes selenium were another and to other ele- sible. This is impaired growth, suddenly taken ments, such as oxygen why NASA’s skeletal abnormalities, and away, we would all and nitrogen. They do policy in its search for poten- defects in carbohydrate and fat be in a lot of trouble, so in chains and rings tial life on other planets metabolism. but that’s because we have and intricate arrays has always been to “fol- Beyond carbon, hydrogen, evolved to take full advantage that are the building low the water.” oxygen, and nitrogen, it is hard of the resources available here blocks of all organisms. Nitrogen would to say what other elements are on Earth. If there were no car- also probably make essential to life. What experiment For example, we depend upon bon on Earth, could sili- the short list of could be designed to see what copper, because somewhere in con, which is just below elements truly kind of life might have evolved our evolutionary history, this ele- carbon in the periodic essential to life. in the absence of any given ele- ment proved effective in certain table, fill the void? Silicon Nitrogen plays ment? Perhaps these are ques- biological catalysts that facili- has four bonding sites, just an important role in tions best left to science fiction tated chemical reactions in our like carbon, and it forms a plant chemistry, and it serves writers! metabolism. We can assume that few short chains, but not nearly past organisms that used copper enough to create the complexity in these catalysts stood a slightly of structures that life processes Correction: greater chance of survival than depend upon. Some science fic- In the October 2009 issue of ChemMatters, an error occurred in the caption those that didn’t. So, organisms tion novels have postulated plan- of Figure 1 (p. 8). The correct caption is: “When light is spread through a using copper continued to flour- ets populated by silicon-based prism, it reveals its constituent colors, going from purple to red.” ish and pass on their copper- life forms. Intriguing, yes, but the Also, the following reference was omitted by mistake from “Selected refer- ences” at the end of the article, “Where Do Chemical Elements Come From,” using genes to their offspring. chemistry just is not there. No by Carolyn Ruth: What started out as an evolution- other element seems to have the Sagan, C. Cosmos; Random House, Inc.: New York, NY, 1980 ary advantage has become a same capacity for life complexity survival necessity. that carbon possesses. 2 Chemmatters, DECEMBER 2009 www.acs.org/chemmatters ® Vol. 27, No. 4 DECEMBER 2009 DEPARTMENTS FEATURES Question from the Classroom 2 Hollywood’s Special Effects: By Bob Becker How Did They Do That? 5 What are the chemical elements that are essential to life? By Diana Lutz Many special effects used in movies are based upon a wide range of CIL ko IS Did You Know? 4 chemicals. Discover which chemicals are used to create fake snow, v E Producing energy with carbonized chicken feathers; artificial skin, and explosions. jo is air pollution as bad as cigarette smoke? The Science of Snowflakes: Profiles in Chemistry: J. L. Kiappes, Crystals from the Clouds 9 ISToCk Silver Medalist in the 2004 International By Andrea Hazard ECHT r LIBB Chemistry Olympiad 17 Snow crystals come in an incredible variety of By Christen Brownlee shapes, including wide flat plates, long thin ENNETH columns, and branched snow stars. Why is that so? k S J. L. Kiappes describes what it’s like to E v I H C take part in the National Chemistry r A o Space Food 11 Olympiad and then the International C N S u By Kathy De Antonis , k Chemistry Olympiad. C To IS Space food needs to be lightweight, compact, and require minimal prep- aration (given that you can’t cook Interested in Competing for the National Chemistry it in space). How do NASA food Olympiad? Here Is a Chance to Test Yourself! 19 scientists do it? By Arden Zipp Spanish translation Try to answer a question that appeared in the National Chemistry available online! NASA Olympiad in 2003. The Vinland Map: The Vikings’ Best Kept Secret 14 By Linda Zajac TEACHERS! find your complete The Vinland Map is either a 13th century map of America that pre-dates teacher’s guide Christopher Columbus or a clever fraud. Learn about the scientists who for this issue at have analyzed the map for the past 50 years and why they have not www.acs.org/chemmatters been able to solve its mystery yet. Production Team Education Division Subscriber Information the cautions contained in the text, or from not Patrice Pages, Editor Mary Kirchhoff, Director Prices to the United States, Canada, and following standard safe laboratory practices. Cornithia Harris, Art Director Terri Taylor, Assistant Director, K–12 Science Mexico: $14.00 per subscription. Inquire Therese Geraghty, Copy Editor about bulk, other foreign rates, and back All rights reserved. No part of this publica- Policy Board issues at ACS Office of Society Services, tion may be reproduced, stored in a retrieval Administrative Team Ingrid Montes, Chair, San Juan, Puerto Rico 1155 16th Street, NW, Washington, DC system, or transmitted in any form by any Marta Gmurczyk, Administrative Editor Barbara Sitzman, Tarzana, CA 20036; 800-227-5558 or 202-872-6067 means, now known or later developed, includ- Peter Isikoff, Administrative Associate Ami LeFevre, Skokie, IL fax. Information is also available online at ing but not limited to electronic, mechanical, Steve Long, Rogers, AR http://chemistry.org/education/ photocopying, recording, or otherwise, without Technical Review Mark Meszaros, Rochester, NY prior permission from the copyright owner. Seth Brown, University of Notre Dame The American Chemical Society assumes no Requests for permission should be directed in David Voss, Medina High School, Barker, NY ChemMatters (ISSN 0736–4687) is published responsibility for the statements and opinions writing to ChemMatters, American Chemical four times a year (Oct., Dec., Feb., and Apr.) advanced by contributors. Views expressed Society, 1155 16th St., NW, Washington, DC Teacher’s Guide by the American Chemical Society at 1155 are those of the authors and do not neces- 20036–4800; 202-833-7732 fax. William Bleam, Editor 16th St., NW, Washington, DC 20036–4800. sarily represent the official position of the Donald McKinney, Editor Periodicals postage paid at Washington, DC, American Chemical Society. The activities in Ed Escudero, Editor and additional mailing offices. POSTMASTER: ChemMatters are intended for high school Ronald Tempest, Editor Send address changes to ChemMatters students under the direct supervision of Susan Cooper, Content Reading Consultant Magazine, ACS Office of Society Services, teachers. The American Chemical Society David Olney, Puzzle Contributor 1155 16th Street, NW, Washington, DC 20036. cannot be responsible for any accidents or © Copyright 2009 injuries that may result from conducting the American Chemical Society activities without proper supervision, from not Canadian GST Reg.