Q: Why do water and oil not mix? Ialways thought it was because oil was less

dense than water, but my teacher said that

water molecules would rather stick to other

water molecules, and oil molecules would

rather stick to other oil molecules, and that's

why they don't mix. He says like dissolves

like. Which one of us is right?

A: A lot of people learn that oil floats onwater because it is less dense, and they inter-pret this to mean that oil and water do not mixbecause oil is less dense. Its low density iswhat makes the oil end up on top of the wateras they separate, but it's not what prevents thetwo liquids from mixing in the first place. For abetter explanation, I have to side with yourteacher on this one: The inability of water andoil to mix (also known as immiscibility) is adirect result of intermolecular preferences,but it turns out that what your teacher is say-ing has a common misconception in it as well.

Before we get to that misconception,though, lets talk polar. Not quite as in northpole but as in diametric, or in plain English,opposite ends. Molecules are held together bycovalent bonds consisting of pairs of sharedelectrons. If one of the atoms in the bond pullsthe electrons more strongly, that tends toattract the electrons toward its end of the mol-ecule. This gives that electron-rich end a par-tially negative charge (-) and the otherendthe atom end where the electrons havemade themselves scarcea partially positivecharge (+). These attractions are known asdipole-dipole attractions. Particularly strongdipole-dipole forces are present among mole-cules where hydrogen is bound to an atomwith a very strong pull on the shared electrons(namely, nitrogen, oxygen, and fluorine), andgo by the name hydrogen bonds. Water is anexample of a molecule that forms hydrogenbonds. This is significant because it makeswater molecules very sticky to one anotherwith the (-) end of one molecule attracted tothe (+) end of a neighboring molecule.

But what about the oil? The bonds withinan oil molecule consist of pairs of electronsthat are shared pretty equally between the par-ticipating atoms. The result? Because there areno (-) and (+) ends, these bonds are nonpo-

lar and the moleculeoverall is considered tobe nonpolar as well.There is, however, ran-dom movement of theelectrons within thesemolecules, and this canlead to temporary lop-sidedness in theircharge distribution andproduce momentary +and - portions of themolecule. These, inturn, can lead to very weak attractive forcesknown as induced dipole-induced dipole, orLondon forces. Because hydrogen bonding inwater contributes a substantial amount ofcohesive energy, over and above the Londonforces present, water is a liquid, whereas othermolecules of similar size but lacking waterspolarity, such as methane, ethane, fluorine, orcarbon dioxide, are gases at room temperature.

And now for the misconception: yourteacher's explanation makes it sound asthough the immiscibility of oil and water is oneof mutual agreement and that there is noattraction existing between a water moleculeand an oil molecule. Some teachers go as faras to say that oil and water molecules repelone another. In fact, the term often applied tononpolar substances such as oil is hydropho-bic, which means water fearing. The truth isthat an oil molecule is very attracted to a watermoleculeeven more than it is to another oilmolecule. Because the water molecule has afixed polarity (a permanent dipole), it is muchmore capable of inducing a temporary dipolein a nearby oil molecule than is another nonpo-lar oil molecule. The (+) end of the water mol-ecule attracts the electrons in the oil molecule

2 ChemMatters, APRIL 2006

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ChemMatters (ISSN 07364687) is published five times ayear (Sept., Oct., Dec., Feb., and Apr.) by the AmericanChemical Society at 1155 16th St., NW, Washington, DC200364800. Periodicals postage paid at Washington, DC,and additional mailing offices. POSTMASTER: Sendaddress changes to ChemMatters Magazine, ACS Office ofSociety Services, 1155 16th Street, NW, Washington, DC20036.

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By Bob Becker

Question From the Classroom

http://chemistry.org/education/chemmatters.html

MIK

E CI

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LSKI

up close to it and this creates a (-) end rightthere next to the water's (+) end. Likewise,the (-) end of the water molecule repels theelectrons in the oil molecule to the far side,and this creates a (+) end right there next tothe waters (-) end. These are known asdipole-induced dipole attractions, and they aresignificantly stronger than the induced-dipole-induced dipole attractions acting between twoneighboring oil molecules.

What this means is, if you were an oilmolecule, you would much rather surroundyourself with water molecules than with othersof your own kind. If that's the case, why thendo oil and water not mix? If it were up to theoil, they would. But it turns out that the dipole-dipole attractions described above are somuch stronger than dipole-induced dipole, thatit is really is the water molecules that are call-ing the shots. Water molecules are far tooattracted to their own kind to ever allow any oilmolecules to come in-between. In short, watermolecules are very cliquish. They will allowother polar molecules such as ethanol orammonia to enter their exclusive company, buta nonpolar molecule: no way! The only mole-cules that would associate with nonpolar mol-ecules would be other nonpolar molecules.

So even though its true: oil and waterdont mix, it is hardly by mutual agreement. Areally impressive illustration of this discrep-ancy occurs when a drop of water is placedon a nonpolar surface such as wax paper.The drop of water beads up into a sphere-barely touching the wax paper. One canalmost visualize the water molecules all gath-ering together in their exclusive club, notwanting to associate with those lowly waxmolecules at all! But when the tables areturned, and a drop of nonpolar liquid isplaced on a polar surface, such as occurswhen a drop of motor oil falls onto a wetpavement, a very different outcome isobserved. Rather than beading up into a tinysphere, the oil drop spreads out into an infini-tesimally thin layerthis is what causes thecool concentric rainbow patterns. In thisarrangement, each oil molecule is in mini-mum contact with other oil molecules, forwhich the attractions are so weak, and inmaximum contact with the much more attrac-tive water molecules.

In this way, like does dissolve like: Polarsubstances dissolve other polar substances,and nonpolar dissolve nonpolar, but for polarsubstances, it's a matter of preference and fornonpolar ones, it's more a matter of settlingfor what you can get!

Vol. 24, No. 2 APRIL 2006

ChemMatters, APRIL 2006 3

Question From the Classroom 2Why do water and oil not mix?

ChemSumerThe Dog Ate My Homework and Other Gut-Wrenching Tales 4

Midge, a fun-loving dalmation has a taste for paper.When she eats $180 in cash and checks, can it berecovered?

Sneeze and Wheeze 7Learning how allergic reactions occur is often the key to living with and controlling the misery they create.

Bling Zinger ... The Lead Content of Jewelry 11Could your jewelry make you sick? For one small child,the answer was yes.

GreenChemBiomimicryWhere Chemistry Lessons

Come Naturally 15From spiders to beetles to mussels, some chemiststurn to nature for inspiration.

Nanomotors 18Some synthetic and others natural, these tiny motors aresimilar to the motors in your favorite household appliances.

Chem.matters.links 20

CMTEACHERS! FIND YOUR COMPLETE

TEACHERS GUIDE FOR THIS ISSUE ATwww.chemistry.org/education/chemmatters.html.

PHOTODISC

PHOTODISC

on theweb

on theweb

on theweb

on theweb

4 ChemMatters, APRIL 2006 http://chemistry.org/education/chemmatters.html

The crimeRecently, Midges owners Kit and Steven

were serving as hosts for a favorite singer/songwriter, an old acquaintance who was intown for a local concert. Things went welluntil the door to the guest bedroom was leftajar. Under normal circumstances the opendoor would not have been a problem, but forlovable Midge, it was a doorway to opportu-nity. There, on the bedside table was $180 incash and a check. So tempting! Not to men-tion delicious!

When the break-in was finally discov-ered, all that was left was a few shreds of thecheck. No sign of the $180 cash. Thus, thewait began. For Kit and Steven, walking thedog took on an entirely new sense of pur-

pose. Picking up after Midge required anadditional close inspection to see if any of thebills made it through her digestive systemintact. The project gave money laundering awhole new meaning. Gross? Definitely. Butluckily, there was some good chemistryworking in favor of retrieving the cash.

The chemistry ofdigestion

At the most fundamental level, the bio-logical processes of digestion and metabo-lism are all about the breaking and making ofchemical bonds.

Basically, digestion consists of breakingfood down into molecules small enough todiffuse through the thin walls of blood ves-

Youd love Midge.

Shes your ordinary,

fun-loving dalmatian

with a great

personality and one

bad habit. She loves

the taste of money,

paper money!

By Michael Tinnesand

The Dog Ate MyHomeworkand Other Gut-Wrenching Tales

The digestive system of a dog.

ChemMatters, APRIL 2006 5

sels. After transport through the body, theycross over into tissues where they areabsorbed and used by living cells.

Food is primarily composed of large bio-molecules such as proteins, fats, and carbohy-drates. The breaking down of food is thebreaking of chemical bonds that hold the mole-cules of the food together. After the moleculesof food are broken down into small enoughpieces for cells to absorb them, they are eitherconsumed completely for fuel or reassembledinto new polymers and other molecules,according to the bodys own blueprint.

The process of breaking bonds in foodincludes a number of key steps. Except foranimals like pythons who swallow their foodwhole, the process of digestion usuallybegins with a physical phase. Chewing breaksthe food into smaller pieces, thereby expos-ing more surface area, which accelerates theprocess of digestion.

Next, most animals have some sort ofspecialized sac or pouch, such as a stomach,where serious digestion gets under way. Inhumans, a strong acid secreted by the stom-ach helps break down tough connective tis-sues and activates a set of biological catalystscalled enzymes. Like all catalysts, enzymesgreatly accelerate the rate of chemical reac-tions without being used up in the process. Asingle enzyme molecule can catalyze a reac-tion thousands of times. But that is not to saythat an enzyme is able to catalyze thousandsof different reactions. In fact, most enzymescatalyze single specific reactions.

This is easier to understand once youunderstand how enzymes work. In what isoften called the lock and key model,enzymes participate in chemical reactionsbased on the shape and structure of thereactants. An enzyme can join reactants(often called substrates) together by offeringadjacent surface features where the reac-tants can fit. In this case, the enzyme makesit much easier for bonds to form in a reac-tion that is already energetically favorable.

Enzymes lower the activation energy, theenergy required to start the reaction, bysecuring the reactants in a geometricallyfavorable position. Held this way, the mole-cules react with little initial energyless than if they had to rely on random collisionsto bring them together. Once bonded, they are released, and the enzyme is free to actagain.

Enzymes can also work to break bonds.In this case a single molecule fits with theenzyme in such a way that one particularbond is stressed. This stress lowers theenergy requirement for breaking the bond.

Because the interactions between theenzyme and the substrate molecules aretotally dependent on shapes, each reactionrequires its own enzyme. Virtually all of the

chemical reactions that occur in living cellsrely on one or more enzymes to allow themto occur at a useful rate. Just like each lockrequires a key with just the right shape, eachchemical reaction requires an enzyme withthe right shape.

And all of this explains why Kit andSteven were optimistic about seeing their$180 again, even after it had been subject toMidges digestive process and the accompa-nying onslaught of enzymes.

enzyme-substratecomplex

substrate enzyme

Activ

e si

te

breakdownof substrate

enzymeready torepeat action

Chem

ical

pot

entia

l ene

rgy

Activated reactants(uncatalyzed)

Reactants

Activated reactants(catalyzed)

Products

Time

The only difference between starch top and cellulose bottom is the way the ring-shaped glucosemolecules are connected (blue-colored bonds).

The red line in this graph shows the loweractivation energy in a catalyzed reaction.

ACS

STAF

F

The lock and key model of enzyme action.

http://chemistry.org/education/chemmatters.html6 ChemMatters, APRIL 2006

Cellulosedefyingdigestion

The enzymes found in humans and otheranimals allow them to digest and metabolizemany, but not all, biomolecules. Cellulose isone example of a molecule that defies diges-tion in many animals. This is an interestingexception because cellulose, a structuralmaterial found in plant cell walls, is made upof the same glucose subunits as digestiblestarch. Glucose is a simple sugar that pro-vides fuel for most organisms. But the slightdifference in the way the glucose moleculesare hooked together in starch, compared withhow they are hooked together in cellulosemakes a big difference in their digestibility.Humans and many other higher animals havethe enzyme required to break the bonds instarch, releasing glucose. But because theshape of the linkage is different in cellulose,the same enzyme will not work. Infact, where cellulose is concerned,humans do not have an enzyme thatwill work. Neither do dogs. Whichbrings us back to Midge.

Paper money is made of cellu-lose in the form of very high-qualitycotton and linen fibers. This cellulosenot only resists the chemicalprocesses that are a part of diges-tion, but also withstands themechanical breakdownchewingand shreddingthat is part of thedigestive process.

As it turns out, most humanseat a fair amount of cellulose in theform of fruits and vegetables. Although wecannot digest it, the cellulose serves asroughage or fiber that gives food bulk andkeeps it moving through the digestive sys-tem. In the end, all of the undigested materialends up being eliminated as feces.

The end ...And so it was that Kit and Steven, with

patience and endurance, were at last able torecover their $180. Midge, like the goose thatlaid the golden egg, eventually passed all ofthe well-chewed bills in her feces.

Maybe you are wondering how animalssuch as cattle, sheep, deer, and goats thriveon a diet of grass or other cellulose-rich food.Can they digest cellulose when humans can-not? The answer is no. None of these animalshave the enzymes required to digest cellu-

lose. Instead they rely on colonies of microor-ganisms living in their digestive systems.These simple microorganisms have the cor-rect enzymes to digest the cellulose and toreassemble the products into starches andproteins. From these products, grazing ani-mals acquire their nutrients. The special rela-tionship between these animals and theirresident microbes is called symbiosistwoorganisms living with each other to the bene-fit of both.

As for Midge, it was a happy ending forall concerned. Withthe cash recovered,Midge eventuallygot out of thedoghouse, andthe songwriterwas even inspired towrite a new song tocommemorate theentire affair.

So what are thechancesin theextremely rare casethat a dog really DID eat your homeworkthat it might show up again undigested on thefront lawn? Not good. The chemicalprocesses that break down cellulose in thepaper-making industry leaves a weaker formof cellulose in the productso weak thatthere is little likelihood of it making its waythrough a dogs digestive system.

Better idea? Save to disk! Avoid mag-nets. But that's another story Photomicrograph of cellulose fibers shows their linear nature.

The paper currency is clearly intact after passing through the dogs digestive system.

Michael Tinnesand is the Associate Director ofAcademic Programs at ACS. His most recent article,Whats So Equal about Equilibrium, appeared inthe September 2005 issue of ChemMatters.

Glucose is fuel for most organisms and the buildingblock for both starch and cellulose. Humans (anddogs) can break down starch into glucose but notcellulose.

PHOT

O DI

SC

Look around and youll see many little chemical factoriesin nature that are nonpolluting and environmentallyfriendly. Inside a leaf or a bug, there lies some sophisti-cated chemistry, often turning out incredible materials

that are the envy of todays chemists and engineers.In fact, you might say that todays industrial chemists

are developing a green thumb. Green chemistry is thedesign of chemical products and processes that reduce oreliminate the use and production of hazardous substances.Green chemists look for new ways to do chemistry that isbenign by design, thus preventing pollution before it starts.

Why are chemists turning to nature for ideas? Thinkabout it. Nature uses renewable sunlight for energy andrecycled starting materials to make a lot of things. Organ-isms synthesize medicines, plastics, and all kinds of otheruseful materials without releasing toxic chemicals into theenvironment or using large amounts of heat or pressure.Natures chemistry embodies many of the principles ofgreen chemistry, using processes that have met the testsof time.

Scientists call the study of these natural chemicalprocesses biomimicry, a term that means imitating life andinvolves applying nature's lessons to new human inven-tions. Janine Benyus, the author of Biomimicry: InnovationInspired by Nature, calls it the conscious emulation of lifesgenius. But that's not to say that every process in nature isnonpolluting. For example, it is well known that animalsrelease carbon dioxide and methane, greenhouse gases,into the environment.

Although biomimicry is getting increased attentiontoday, several famous inventions of the past were inspired

by nature. Take the telephone, for instance. Alexander Gra-ham Bell studied the human tongue and eardrum to helphim design the first telephone. The Wright Brotherswatched birds gliding in the wind for shaping airplane wingsbefore taking the first flight. And nearly everyone is familiarwith synthetic Velcro, which was inspired by the way thetiny hooks on seed pod burrs attach to the loops of threadin cloth.

Whether forms, processes, or systems, biologyincludes a wealth of ideas for chemists and engineers.When scientists apply the methods and systems practicedin nature to cutting-edge research challenges, creative andamazing scientific breakthroughs often occur.

Spiders spin webs strongerthan steel

Dragline silk from a golden orb weaver spider is fivetimes stronger than steel (when compared gram for gram),

ChemMatters, APRIL 2006 15

GreenChem

How do they do that? How do spiders spin a web that's strongerthan steel? How do bombardierbeetles launch chemical bombs attheir enemies without hurtingthemselves? How do tiny musselsstick to rocks in the pounding surf?How do green plants generate asteady supply of safe and renewable energy?

By Kathryn E. Parent and Jennifer L. Young

BIOMIMICRYWhere ChemistryLessons ComeNaturally

PHOT

ODIS

C

16 ChemMatters, APRIL 2006 http://chemistry.org/education/chemmatters.html

and can absorb five times the impact force ofKevlarthe synthetic fiber of bullet-proofvestswithout breaking. Whats more, it canstretch 40% longer than its original length.For the spider, the durability and strength ofsilk means food. And for humans, it couldmean an amazingly useful fiber that can bemade from safer and less hazardous chem-istry. Science writer Steve Miller describes theproperties of good web fiber in a February2001 ChemMatters article: It must be strongenough to bear the weight of a bungee-jump-ing spider, flexible enough to withstand theimpact of a flying insect, and stable enough tolast for days. And it cannot require moreraw material than the spider can replenishfrom ordinary food resources. Even the U.S.military has taken notice. The U.S. Army hasinterest in a manufactured version of draglinesilk for applications such as catching fighterjets as they land on aircraft carriers.

How does a spider make such an incredi-ble fiber that humans have not yet fully repro-duced? Scientists are still studying thechemical composition of the spiders silk. Sci-entists know that spider silk is a protein andhave identified the amino acids that are itsbuilding blocks. Glycine and alanine are themost abundant amino acids in the silk (seeFigure 1). The three-dimensional structure ofthe fiber, which gives it the strength and flexi-bility, results from how the amino acid build-ing blocks interact with each other. As a resultof the diversity of amino acid interactions,some parts of the silk fiber are highly oriented,like uncooked spaghetti, and other parts arevery nonoriented like cooked spaghetti.

To make the silk fiber, the spider synthe-sizes liquid protein by putting together theamino acid molecules and squeezes the pro-tein through a spinneret (i.e., to spin thefiber). When it exits the spider, the soluble liq-uid protein becomes an insoluble, highlyordered, and extremely strong fiber. With thisknowledge, scientists are trying to make afiber that is similar to spider silk. This much iscertain: spiders dont use the high pressures,high temperatures, or corrosive acids oftenused in chemical syntheses. In manufacturingKevlar, for example, industrial chemists relyon hot concentrated sulfuric acid. Nylon fiber,used in ropes and cords for rock climbing andparachuting, is manufactured under condi-tions of high pressure and temperature. Thegolden orb weaver spider manages to producea high-performance fiber using chemistry mildenough to occur inside their bodies.

The bombardier beetle bomb

Bombardier beetles can fire, literally, amixture of chemicals at predators. To preparefor attack, the beetles produce and store twochemicals, hydroquinone (C6H6O2) and hydro-gen peroxide (H2O2).

When the mixture of chemicals is pushedfrom the storage reservior into the firingchamber, enzymes in the chamber wall reactto release free oxygen (O2) and steam (H2O).They also oxidize the hydroquinone to benzo-quinone, which is an irritant (see Figure 2).The resulting reaction is extremely exother-mic. Heat and pressure force the chemicalspray out an opening in the beetles abdomenwith a loud bang. The chemistry is simple,but the biology is beautiful said Jerrold Mein-wald, a researcher at Cornell University.Despite the heat, pressure, and irritatingchemicals emanating from its body, the beetleremains largely unaffected. Unfortunately, thenews isn't as good for its enemies.

The March-April 2004 issue of AmericanScientist features the research of Andy McIn-tosh, a professor of thermodynamics andcombustion theory at the University of Leedsin England. He is working to apply the bom-bardier beetles methods to find a better wayto reignite aircraft gas turbine engines.Beyond engine reigniters, McIntosh envisionsfuture applications of the bombardier beetlesdesign, including rocket technology, automo-

bile airbags, and unmanned aerial vehicles,though all of these are beyond the scope ofhis current study. "I think the natural world isfull of excellent designs that we can learnfrom," McIntosh says.

Blue mussels make glue

Visit the seashore and you'll find mus-sels clinging steadfastly to rocks, despite thecrashing surf. How do they do it? Professor J.Herbert Waite from the University of Delewarehas been researching this question for morethan 30 years. The mussels are able to applytheir protein-based glue underwater, where itcures and sticks to nearly anything amidst theharsh ocean. They do it with chemistryWaite realizes. But so far, no chemist has suc-cessfully synthesized this incredible marinesuperglue. Clearly, the product would be aboon to boaters of all descriptions. With aglue like that, they would no longer have todry-dock boats for repairs.

Professor Kaichang Li, a wood chemistryexpert at Oregon State University, used mus-sels as his model for developing a new soy-based wood adhesive. He explains, Inspiredby the strong and water-resistant binding ofmarine organisms such as mussels to rocksand other substances, we are investigatingconversion of renewable natural resourcessuch as soy protein, carbohydrates, and ligninto strong and water-resistant wood adhe-

OH

OH

H2O2

O

O

H2O O2

Hydroquinone Benzoquinone

+ +

Hydrogen peroxide

Catalyst+ + Energy

Water(steam)

Oxygen(gas)

Heat

H

C COOHH2N

H

CH3

C COOHH 2N

H

glycine alanine

Figure 2. Oxidation of hydroquinone.

Figure 1. Chemical structures of glycine and alanine.

sives. He noticedthat the chemicalstructure of the pro-teins in the musselsglue included a lot ofringed hydroxylchemical structures.By modifying soyprotein (e.g., tofu) toincorporate more ofthese types of struc-tures, Li has devel-oped a new glue thatis stronger and more

water-resistant than the traditional formaldehyde-based adhesives usedto make plywood. Even better, the glue doesnt release hazardous airemissions during manufacturing processes or from the finished ply-wood boards. Thats good news for the environment, for plywood man-ufacturers, and for consumers of plywood.

New directions in biomimicryresearch

Writer Alexandra Goho, in a Science News Online February 12,2005, article, highlighted several chemists who are using nature forinspiration in their laboratories. For example, Dr.David Liu at HarvardUniversity has found ways to use one of natures premier templates,DNA, like a molecular laboratory for synthesizing chemicals in minisculebatches. DNA controls the order and amount of chemicals that reactduring a given process, limiting the number of undesired by-products.

At Cornell University, Dr. Tyler McQuade looks to cell biology forinspiration to develop an assembly-line system to make drugs likeProzac. His microcapsule enzyme-mimic approach, controls the order inwhich reactions take place, minimizing separation and purification stepsthat typically generate large amounts of waste.

Dr. John Warner at the University of Massachusetts-Lowell recog-nizes seashells as models for lowering the energy required to producesolar cells. To make their shells, mollusks rely on small organic mole-cules to choreograph the assembly of calcium carbonate (CaCO3) intoelaborate mineral structures. When Warner looked at films of titaniumdioxide (TiO2), used as an alternative to silicon (Si) metal for solar mate-rial, he saw a resemblance to the structure of seashells. So, Warner

tried using small organic molecules with multiple carboxylic acids(RCOOH) to assemble titanium dioxide particles into films of solar mate-rial. He was able to accomplish it at room temperature, a tremendousenergy savings over traditional manufacturing methods that requireheating titanium dioxide (TiO2) films at 500 C.

The examples above show the incredible variety in the researchchemists and engineers approach using biomimicry. Imagine what wecan create, using examples in nature to find new and better ways todesign materials, processes, and systems.

ChemMatters, APRIL 2006 17

ReferencesBellis, M. Famous InventionsA History of Inventions

Available at http://inventors.about.com/library/bl/bl12.htm (accessed Jan. 20, 2006).

Benyus, J.M. Biomimicry: Innovation Inspired by Nature. New York:Morrow, 1998.

Biomimicry Guild. Available at http://www.biomimicry.net/ (accessedJan. 20, 2006).

Goho, A. Chemistry au Naturel Science News Online. 167, 2005.Available at http://www.sciencenews.org/articles/20050212/bob8ref.asp or http://www.phschool.com/science/science_news/articles/chem_au_naturel.html (accessed Jan. 2006).

Li, Kaichang. Kaichang Li Available at http://woodscience.oregonstate.edu/faculty/li/ (accessed Jan. 20, 2006).

Ross, G. Insect Inspiration American Scientist Online. 2004, March-April. Available at http://www.americanscientist.org/template/AssetDetail/assetid/31218 (accessed Jan. 20, 2006).

Saulnier, B. Chemical Warfare Cornell-Magazine On/Line. 103, 2000.Available at http://cornell-magazine.cornell.edu/Archive/July2000/JulyBugs.html (accessed Jan. 20, 2006).

Wikipedia: The Free Encyclopedia. Biomimicry Available athttp://en.wikipedia.org/wiki/Biomimicry (accessed Jan. 20, 2006).

Wikipedia: The Free Encyclopedia. Bombardier Beetle Available athttp://en.wikipedia.org/wiki/Bombardier_beetle (accessed Jan. 20,2006).

Wikipedia: The Free Encyclopedia. Velcro Available athttp://en.wikipedia.org/wiki/Velcro (accessed Jan. 20, 2006).

Kathryn E. Parent and Jennifer L. Young are staff of the American ChemicalSocietys Green Chemistry Institute (www.greenchemistryinstitute.org).

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The Consumer ProductSafety Commission

The Consumer ProductSafety Commission (CPSC) is thegovernment agency responsiblefor protecting the American publicfrom potential injury by more than15,000 consumer productsexcluding cars, foods, and drugs.The CPSC issues product recallsand safety warnings; it also pro-vides consumers with a forum forreporting safety products. Forexample, the CPSC was intimatelyinvolved with the recall of thesome of the jewelry described inBling Zinger. For more informa-tion on the CPSC, visithttp://www.cpsc.gov/index.html.

Not even asthma canstop Olympians fromgoing for gold!

Exercise-induced asthma isfairly common, impacting upto one in five athletes. Theseathletes can suffer fromshortness of breath, chesttightness, and wheezingeither during or after exer-cise. Even Olympiansaren't immune to this res-piratory disease. Accord-ing to the American

Academy of Asthma, Allergy andImmunology (AAAAI), up to onein six of these world class athletessuffer from asthma. For moreinformation on exercise-inducedasthma, its triggers, and symp-tom management, visithttp://www.aaaai.org/patients/publicedmat/tips/exerciseinducedasthma.stm.

More on nanomotorsSynthetic nanomotors are an

exciting and elegant creation atthe interface of chemistry andphysics. In Nanomotors, thesynthetic nanomotor created byAlex Zettl, professor of physics atUC Berkeley and his graduate stu-dents is described as a gold rotorattached to a carbon nanotubeshaft. To view pictures and videoof this 500-nm motor in action,visit http://www.berkeley.edu/news/media/releases/2003/07/23_motors.html.

Chemists celebrateEarth Day

Thats right. The Ameri-can Chemical Society willobserve Earth Day on April22. The theme for the 2006celebration is Dig It. The

community event forChemists Celebrate EarthDay 2006 is Plant It forthe Planet. Celebratethe chemistry of thesoil and plants byhosting activitiesthat will benefit the communitylike planting flowers, trees, grass,

etc. This activity willbring the community

together for a fun-filled day! To help

celebrate the day,a series of hands-

on activities are availablefor teachers and students athttp://chemistry.org/earthday.

Renewal notices for 2006-07 will be mailed in earlyApril. Renew or subscribe now before the hectic

end of the school year.

Last year, we added multiyear subscriptions so that you can lock incurrent rates for two or three years.

Look for the option on your renewal notice.

Also, complete your classroom ChemMatters set with our 20-year CD.

Youll find every issue from 1983 through2003 along with every ChemMatters

Teachers Guide ever published. Weve made it easy to search for your

favorite everyday chemistrytopics featured inChemMatters overthe years. The price

is only $25! Call 1-800-227-5558, or order

online at

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http://chemistry.org/education/chemmatters.html.

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