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RONALDDELORENZO Middle Georgia College Cochran. GA 31014
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This column will publicize the applicationsand analogieswhich our readers have found tobe useful when presenting general chemistry to their students. Applications and Analogies can help students to better understand some of the difficultconcepts frequently encountered in chemistry. The blending of chemistry with current applicationsand analcgies places both chemistry and student into a familiar setting, stimulates student interest, and produces an educated (versus trained) student. This integration of material results in a greater appreciation and understanding of political, religious, economic, historical, and scientific aspects of life. Applications and analogies are fun to teach and more interesting to learn than a collection of facts and theories isolated from the surrounding world. Applications and analogies add another dimension to chemistry: they increase understanding and retention time. Share your favorite chemical applicationsand analogies with ua by sending your material ta the feature editor. Your material should be sent in triplicate. Manuscripts should not exceed three double-spaced typewritten pages. The more concise the better.
California Earthquakes: Predicting the Next Big One Using Radiocarbon Dating Ron DeLorenzo Middle Georgia College Cochran, GA 31014 When studying radiochemistry, rather than use imaginary numbers to date nonexistent artifacts, why not use actual experimental data to determine the ages of current items of interest? Here's an illustration. The only two major earthquakes which have struck California in recorded history did so when California was relatively unpopulated. Now that California is the most heavily populated state in the union, a maior earthquake could result in thousands of deaths. ~ c i e n t i s kare trying to develop mndels of the California iituation which ran accurately -predict future earthquakes. Were the last two major earthquakes flukes? Were there other major earthquakes in California's past? If there were others, with what frequency did they occur? Did they occur every 100 years? Every 1MO years? Knowledge of California's earthquake history would be valuable information in piecing together a model which could predict future earthquakes. Recently, a 13-ft trench was bulldozed in a marsh which straddles a small nortion of the San Andreas Fault about 55 miles northeast of 1.0s Angeles. Several breaks were found in the strata of this trench indicating sudden shifts of several feet between the land masses on opposite sides of the fault. These shifts are signs of major earthquakes. The age of the organic material (material that was once living) found in the layers was determined by radiocarhon dating. In 1979, the organic material found in the broken strata layers had the following activities in cpmlg 13.91, 14.00, - C: 12.91, 13.05, 13.37.13.53, ~
Ron DeLorenzo is an Associate Professor in the Department of Chemistry at Middle Georgia College. He is also Campus Coordinator for the computing facilities and teaches a course in FORTRANfor Math and Engineering majors. Ron received his BS from St. John's University in 1963and the MS and PhD in Physical-Inorganic Chemistry from Lowell Technological Institute in 1967 and 1970, respectively. Ron is very interested in relating course material to the real world. He has just completed a text entitled "Chemistry: Pmhlem Solving and Comprehension Enhancements Through Applications, Anecdotes, and Analogies" which will be appearing in print sometime in early 1981. Ron is actively involved in Chemical Education and Computer-Assisted Instruction.
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14.39,14.88, and 15.08. Calculate the date of the oldest known major earthquake in California. What is the approximate frequency of these earthquakes? The oldest layer is the layer with the smallest activity. The activity of the oldest layer is 12.91 cpmlg C. 15.3 cpm/gc = 1405 yrs t = - 2.303 log-No - 2.303 12.91cpmlge N 1-21 x 10-"log -~ yr
In 1979, the age of the oldest layer was 1405 years. The earthquake occurred hack in 576 AD. The dates for each of the broken +ata are 576,668,863, 968,1193,1248,1473,1748, and 1860 AD. The interval hetween quakes varies from as little as 55 years to as much as 275 vears. The averaee internal between maior is about 160 . auakes . years. This is important to know, i.e., that major earthquakes strike California about everv I60 vears and nor, for example, every thousand years.
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C Properly Opening a Beer can' and Boyle's Law R o n DeLorenzo Middle Georgia College Cochran, GA 31014 If you've ever shaken a can of heer before opening it with a can opener or popping the flip-top, you know the mess that can occur when the beer sprays from the can. Some of the more experienced beer drinkers know of a technique which eliminates the mess: tap the sides of the heer can before opening it. Tapping the sides prevents the heer from spraying out. Let's see what Boyle's Law has to do with this. When you shake a can of heer, the tiny gas huhhles created by the shaking adhere to the sides and bottom of the can. When a can of heer is opened, the pressure inside the can is reduced. The pressure reduction causes the gas huhhles adhering to the inside wall to expand, pushing out the heer and making the aforementioned mess. Tapping the sides of the heer can would cause the tiny adhering gas huhhles to rise to the top of the can where their expansion (when the can is opened) would only be noticed by a rush of gas from the can (as opposed to a rush of heer). Both "Ao~lications and Analoeies" are from DeLarenzo. Ronald. .. "Chemistry: I'nhlem Solving and Comprehrnsim Enhancements Through Applications, Anecrlntrs, and Andogiei," D.C. Heath and Company, Lexington. MA. 1981. volume 57, Number 8, August 1980 / 601
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