application~ and analogief I
edited by: RON DELORENZO Middle Georgia College Cwhran, Georgia 31014
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Editwk Note: Harold Scheintaub said perfectly: "We lecture, we draw diagrams we offer exempiesbecause a student is more likely to understand concepts if we present them in more b n one way. Analagles are another vehicle. By reiatlng unfamiliar ideasto the familiar, we provide a starting point for thought." (Scheintaub,H. Scl. reach. 1987, (April), 29.1
The Collision Theory and an American Tradition Lee A. Krug Unionviiie High School Unionville. PA 19375
In the spring when I am teaching kinetics, the rest of the world (including my students) has tuned into baseball, one of our American traditions. In order to capitalize on this interest, I compare the three requirements of the collision theorv of molecules (i.e.. the molecules must collide., thev musthave sufficient ;neigy, and they must have the correct eeometrv) t o the three conditions necessaw for a baseball player to hit an outside-the-park home run.
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Journal of Chemical Education
T o make this comparison as visual as possible, I ask for a volunteer pitcher to throw a Styrofoam ball to me, the batter. Using a plastic or cardboard hat, I ask the students to predict which hit halls will he home runs. After several attempts and failures a t bat I encourage the students to determine what requirements are necessary for the elusive home run (i.e., contact with the ball, power, and proper angle between the ball and bat). If one of these conditions is omitted, I will demonstrate during my next several at-hats which one is missing. If contact was not mentioned, I swing hard and miss the ball altogether. If power was omitted, I pop up or ground one. At the conclusion of this little demonstration, hovefullv, the students will be able to see the analogy hetween.hitti&, home runs in haseball and the collision theorv of moleculeii in chemical reactions. Following is a chart for your comparison: Basbail
Reactions
1. contact between ball end bat 2. sufficient power 3. Correct angle between bail and bat
collision between moiecules sufficient energy (activationenergy) correct geometry between moiewles when they collide
