Information:
• Write-ups for academic year SMILE meetings for the current semester may be found at http://www.iit.edu/~johnsonp/acysmile.html, and write-ups from previous semesters are permanently located at http://www.iit.edu/~smile/biweekly.htm.
• Hang tags, which permit parking in the IIT lot on the Northeast corner of 31st Street and State Street, were passed out at the meeting. These hang tags should be hung from the rear view mirror of your vehicle, so that the writing is visible from the outside.  They are valid only on Tuesday afternoons after 4 pm, from now until the end of the Spring semester 2005.
• Carol Giles [Collins HS] called attention to her newly published book, Gifted and Gone:  Proverbs, Quotations, Sayings and More. The book is described as " A collection of humorous and thought-provoking quotes from all aspects of human life." It is available from iUniverse Publishing [http://www.iuniverse.com].  For details see the following site: http://www.iuniverse.com/bookstore/book_detail.asp?&isbn=0-595-30613-6.

Chris Etapa  [Gunsaulus Academy]           The Ecosphere
Chris' son bought an "ecosphere" for her for about $20 (oddly, at an electronics store). It is a glass globe that is sealed. It is 3-4 inches (8-10 cm)  in diameter. It contains brine shrimp (5) and algae and about 6 snails.  The system is self contained and self sustaining. It is about 3/4 filled with water. The algae make oxygen for respiration of the snails and shrimp which make CO₂ for the algae. The algae presumably make biomass to support the growth of the shrimp and snails. Enough nutrients (presumably for algal growth) are included in the solution to support at least 2 years of sustainability. We enjoyed passing the ecosphere around and examining it close up.  Very interesting, Chris!

Terry Donatello [ST Edwards School, Elmwood Park]          Atoms and how to show some things about atoms, even though you can't see atoms
(in a sense a version of the Rutherford gold foil experiment [http://www.chemsoc.org/timeline/pages/1911.html] )  We all welcomed Terry back with great enthusiasm!

• Terry distributed clay balls about 2 inches (5 cm) in diameter, along with toothpicks. Toothpicks were used to probe into the clay balls inside each of which Terry had hidden something. Using the toothpick probe and sticking it into the clay balls, we tried to infer what is inside without actually seeing it. Strategies included sticking numerous toothpicks into the clay balls from all different directions and with variation in the depth of sticking. The more toothpicks, the better, and some groups used  up to 20 or so to complete their probing. With regard to accuracy, our results were mixed! Objects included a wing-nut, a plastic bottle cap, and half-circle bracket.
  
• Terry had taken a shoe box and hidden something inside. She cut out the ends and replaced them with flaps of construction paper that had been cut into strips to allow a marble to go in and out of the shoe box when rolled inside, without allowing us to see what is inside. Also, the marble would ricochet backwards because of what was inside the box.  Again, this is a nice model of the Rutherford experiment.
  
• Terry put 4 steel balls or rubber balls in an aluminum pie pan, and made little indentations in the bottom of the pan to hold the balls stationary and rolled marbles down a ramp made from a 1 foot ruler to hit the balls. We tried to do a lot more similar permutations of this technique, using rubber and steel balls, as well as marbles as targets (in the pie pan) and as projectiles (rolling down the ramp).  We tried to see the results with a certain type of projectile striking a given target at a certain speed and location, etc.  Once again, very interesting!.

These were good models of the Rutherford experiment!  Thanks, Terry.

Ken Schug [IIT Chemistry]     Ken's "Chemistry Road Show"

• First, Ken showed two 10 oz (300 ml) pop bottles that were  both about 2/3  filled with a reddish liquid. They looked the same, but were they? How could we decide this? Density? pH? Smell? Open the bottles and mix them together was Ken's idea. When we mixed them, they appeared to be the same, as there was no separation of the two into different layers, etc. Ken confirmed that they were the same, a solution of CoCl₂. The color comes from the Co²⁺ ion.

  We investigated further. One bottle was warmed (in a warm water bath) and the other was chilled (in an ice bath).  The chilled one became redder, but the warmed bottle turned blue! Co²⁺ ions hydrated with 6 waters (pink) and (CoCl₄)^2- (blue) were in equilibrium with each other, and this equilibrium point was shifted by the temperature. The different colors of the two species are due to the different electron energy levels between the two.  A  Co²⁺ ion in "cobalt glass" that is structured similarly to the (CoCl₄)^2-  gives cobalt glass its distinctive blue color.
  

• Ken suggested that flour could be a renewable fuel! He poured out some flour (the flour had been pre-dried in an oven) into a metal dish and tried to light it with a match (without success). He then poured out some flour into a small plastic funnel attached to about 2 feet of rubber tubing. With the lights out, Ken blew gently on the tubing to make an aerosol of the flour above the funnel while he put a lighted match in. We got a great flame! The greater oxygen to flour ratio of the aerosol allowed the flour to burn.  This is the same principle that sometimes leads to grain elevator explosions!
  
• Into one baggie (sealable with a tie) Ken put hydrogen peroxide solution and dry yeast. Peroxidase in the yeast converts the peroxide into water and oxygen; the oxygen collects in the baggie when it is tied off. We could see the results of the reaction as a foaming (the reaction gave off heat as well, and Ken could feel the baggie get warmer). A baggie just filled with air was pierced with a lighted cigarette, but nothing happened. The yeast-peroxide baggie pierced the same way resulted in a bright glow when the cigarette pierced the baggie; this was due to the greater concentration of oxygen inside this baggie than in ordinary air, which supported a greater amount of combustion. 

Notes taken by Benjamin Stark.