Cereal Clusters

My younger daughter started finding clusters in her chocolate-flavored puffy round cereal today.  We did not keep rigorous records, but as the picture suggests the dimers were more common than the trimers, which were in turn more common than the tetramer (this tetrahedron was the only one we saw).  This brings to mind some different ideas.  For example it might make a good science fair project to survey the cluster populations and show that the bigger the cluster, the more rare it becomes.  This in turn leads me to think about probabilities of bimolecular and termolecular collisions in kinetics and wonder if some connection can be made to these clusters.  Well, at the very least, the clusters remind me of groups of hybridized orbitals associated with an atom.  The dimers remind me of two sp hybridized orbitals, the trimers remind me of three sp2 hybridized orbitals, and the tetramers remind me of four sp3 hybidized orbitals.

LED emission spectra

A student gave me a decoration that contains red, green, and blue LEDs that light up apparently randomly alone and together.  I used an Ocean Optics USB2000 spectrometer with a fiber optic sensor to study the glow.  The Overture software that I used has this cute feature that overlays colors on the visble light spectra.  The emissions from each color of LED (red ~650 nm, green ~515 nm, and blue ~465nm) are quite clear in these spectra.

The Pie in Pyrex

I was reading an article in the Fall2012/Winter2013 issue of "Chemical Heritage" (R. Blaszczyk, Cooking with Glass) about Pyrex bakeware.  Apparently when Corning developed borosilicate ovenware, the first dish produced was a pie plate.  The names considered for the glass were thus Pie-Rite or Py-Right, but then it was changed to Pyrex in 1915 (to rhyme with Nonex, another brand of Corning glass).  Seems appropriate to mention pie on Thanksgiving!  Hope yours is good.

Starch-containing packing peanuts

Adding water to starch-based packing peanuts begins to dissolve them (conventional polystyrene peanuts are not soluble in water).  If just a LITLLE water is added to the peanuts, only their edges dissolve and they beome sticky.  The sticky peanuts can be then stacked into larger structures.  Colored versions of these sorts of packing peanuts are marketed as "Nuudles".  This demonstration illustrates concepts of like dissolves like, solvent welding, and recyclability of these starch-containing polymers.

Hydrogen Balloon Fail

I was doing a demo show yesterday, and when my helper attempted to detonate a balloon containing hydrogen and oxygen gas with a lit candle on a stick, the ballon simply popped rather than detonating.  This has happened a handful of time, typically with pure hydrogen in the balloons rather than a hydrogen-oxygen mix.  What I think is happening is that when the candle flame approaches the balloon too slowly, its heat weakens the balloon and causes it to fail.  The gases are then released in such a way that they do not detonate in contact with the frame.

Fake Frost and Window Crystals

Saw this fake frost on the store windows at a Bass Pro Shop today.  I do not know how it was made, but it shows pretty crystal patterns.  For comparison, the van windows have real frost.  One can saturate water with Epsom salt (magnesium sulfate) and paint the solution on dark-colored paper.  When the water on the paper dries, the white salt crystals look like frost. When I was a graduate student some twenty years ago, I would occasionally work with organic compounds that melted at temperatures not far above room temperature.  Sometimes a flask with a film of this melted liquid would cool in my hands.  As the film solidified, pretty crystal stars would form along the walls of the flask.  This was always fun to see.  Update on 6-4-13:  today one of my kids got some Crayola Crystal Effects Window Markers.  When the marker ink dries it makes pretty crystal stars.

National Chemistry Week 2012

The theme for this year's 25th Annual National Chemistry Week (October 21-27, 2012) is nanotechnology.  In the spirit of that I set up a display at Bradley University about nanotechnology and a ruler next to a sign saying "How tall are you in nanometers?"  The idea is adapted from a display that I saw at the University of Texas-Austin last year.