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

• Terry Donatello helped Val III by asking questions, and established that sound from the clock gets to our ears by traveling through the air.
• When we wrapped the timer in a newspaper and put everything inside a box, we could still hear the ticking.
• We put the timer on the table, and put our ear on the table.  We could still hear the ticking through the table.
• We put the timer inside a metal can, and closed the lid.  We could hear it.
• We put the timer inside a paper bag, and could still hear it. 

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:

• 1/4 teaspoon of pepper
• one drop of liquid soap
• 1/4 teaspoon of sugar

Then, we started over using these ingredients in order:

• 1/4 teaspoon of cinnamon
• one drop of liquid soap
• 1/4 teaspoon of sugar

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]:

• Chain structure, the 5 carbon atoms lay in a row, with the inner 3 C atoms attached to 2 H atoms, and the outer 2 C atoms attached to 3 H atoms.
•  Branched structure, a central carbon atom was connected to 4 outer carbon atoms, each of which was also attached to 3 H atoms.

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

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