High School Biology-chemistrySMILE Meeting
27 March 2001
Notes Prepared by Porter Johnson

Val Williams Jr (Bass School) Traveling Sounds
We listened carefully to the ticking of a timer that his son, Val III, held up

The conclusion is that sound travels through air, as well as wood or plastic (the table), paper, and cardboard.  The volume and the quality of the sound were changed under these various conditions.  Karlene Joseph suggested holding the timer against the window, as well as against the chalkboard, to show dramatic changes in the volume of sound.  A discussion of resonators to produce the sensation of sound through vibrations, with applications for the hard-of-hearing, followed.  Our eardrum system is an excellent resonator!

Mary Scott (Williams School) The Great Pepper Chase
In this activity we investigated surface tension. We took an aluminum pie pan half full of water, and added small amounts of these ingredients in succession:

Then, we started over using these ingredients in order:

We concluded that soap reduced the surface tension of water, causing the floating pepper / cinnamon to go to the rim, whereas sugar increased it, causing them to go back toward the center.  We repeated the experiment with varying amounts of the ingredients, to study the effect.

Karlene Joseph (Lane Tech HS) Two Liter Bottle Tornado Makers
told a story about the two connected two-liter bottles [one initially full of water and one initially empty] that have been used in the summer SMILE program for many years to illustrate the action of a tornado. She produced a simple tornado maker on the spur of the moment at a school party using empty pop bottles.  Her students were genuinely impressed with the device, which none of them had ever seen.  She showed us the apparatus in action.  When the apparatus is inverted, the water in the top bottle can be made to stay there because of air pressure in the bottom and surface tension of water in the connecting tube.  Agitation interrupts this quasi-stable situation, and water flows to the bottom bottle, a vortex being set up in the process. 

Therese Donatello (St Edwards School) Organic Chemistry / Structures
She passed out a handout containing two different structures for the hydrocarbon Pentane [C5H12]:

These two hydrocarbons are isomers, with the same chemical formula but different molecular structure.  In general, they have different chemical properties.  By contrast the hydrocarbon  with a pentagonal carbon structure  C5H10, which has each carbon atom attached to 2 H atoms, is not an isomer of C5H12.  The class considered making various isomers of Butane, C4H10. The group then examined wooden balls with holes in them, to which rods could be attached to build molecular models..  Here is the correspondence of the element in question with the balls

Color Element:
Number of Holes: 
Black Carbon: C 4
Yellow Hydrogen: H 1
Red Oxygen: O 2

Holes in the block represent valence electrons, which can be given or taken. The number of valence electrons to be given or taken is determined by the position of the element in question in the Periodic Table [http://www.ptable.com/].  Models can easily be made for C5H12 [Pentane], C4H10 [Butane], CH3OH [Methanol], C2H5OH [Ethanol], and C3H7OH [Isopropyl Alcohol].  This lesson will be continued next time.

Notes taken by Ben Stark