Chemistry Everyday for Everyone edited by
view from my classroom
David L. Byrum Flowing Wells High School Tuscon, AZ 85716
Integrating High School Chemistry with Environmental Studies and Research Jack Randall Interlochen Arts Academy, 11461 Fredmar Dr., Interlochen, MI 49643 Two students stood along the banks of the Little Betsie River. Chris wore hip waders; he was carrying a graphing calculator connected to a device that would record pH readings at the push of a key. Elizabeth, dressed warmly but still shivering in the mid-November chill, held a clipboard and a spiral notebook. Four students and one teacher were in the stream, each gathering a specific piece of information about the languid brook that connected two lakes in northern Michigan. Environmental Chemistry? Not really, more like everyday Chemistry. On the cover of the notebook Elizabeth carried was an inscription done in neat, floral handwriting: “Stream Testing, 1995–96”. The notebook was only weeks old but showed the wear and wounds of frequent trips outdoors. The cover was warped and stained and the ink on the first five pages was smeared in the lower right hand corner. Well, it was a stream-testing notebook, Elizabeth the Bookkeeper would explain, and streams were generally pretty moist. Elizabeth’s job, as a member of the six-person field team, was to carefully record all of the water testing data that her colleagues, who were studying Introductory Chemistry at Interlochen Arts Academy, would gather throughout the school year. She earned the honor initially by default. When this component of IntroChem was described to her class, Elizabeth flinched noticeably at the idea of donning hip boots and slogging in a river. Most of her classmates were more than willing to wade the stream. A side comment was heard “I didn’t think we’d get to go outside for a Chemistry class.” She nearly leaped out of her chair to volunteer when she heard the teacher say, “And we’ll need one person to stay on shore to record data.” Elizabeth the Bookkeeper. Chris stayed on the bank of the Little Betsie for a moment because something in the previous day’s class discussion struck him as curious. It was a pair of terms that had been written on the chalkboard: System and Surroundings. The two terms were discussed as thermodynamic principles
Jack Randall has been a member of the faculty at the Interlochen Arts Academy (MI) since 1987. He teaches Introductory Chemistry, Advanced Placement Chemistry, and Organic Chemistry. In preparation for his teaching career, Jack practiced research chemistry as a Technical Services and Development Chemist for the Dow Chemical Company. He has found it especially rewarding to observe science through the eyes of artistically gifted young people. Jack is the co-author of the book Chemistry with CBL (Vernier Software) and the author of Sensor Sensibility (Key Curriculum). He has conducted numerous workshops in the use of graphing calculator/CBL technology for the science classroom. He is the member of the development and instructional team for the CHEM/BIO institutes, a part of the Teachers Teaching with Technology program.
were introduced and outlined. Chris fought with the implications of those terms, not quite following the teacher’s analogy (“Analogies are used to make definitions more confusing,” Chris asserted one day after class.) Now, standing next to a gentle river in a setting quite unlike his metropolitan Detroit neighborhood, two confusing terms began to make sense. He stood on the bank, looking down at the ground around the feet of his floppy rubber waders, and murmured, “Surroundings.” He eased into the stream, suddenly knee-deep in nippy water (“It’s 11.8 °C in this stream!” said Abby as Elizabeth wrote in her notebook), and said, “System.” Then Chris climbed back onto the bank, grabbing an overhanging tree limb for support. He said, “Surroundings.” The look on his face was a mixture of sober recognition and the teenage smirk that appears when a student “gets it” and realizes that what he got wasn’t that tough to get. The teacher, observing Chris’s epiphany, shared the smirk as their eyes met. Chris repeated this process twice more before joining the others in the stream. He moved near Matthew, who was rechecking a conductivity reading that he had just taken. Matt shouted a number to Elizabeth, then turned to Chris. “What were you doing over there, were your boots leaking?” Matt asked. Chris lowered the pH probe into the stream at Checkpoint #3 (near an exposed boulder on the north side of the stream, and the easiest place to step into the water) before answering, “Homework.” This response was a bit too obtuse for Matt; he scrunched his nose and raised his eyebrows. Matt replied, “Oh,” and resumed his testing. The profile being conducted at the site was typical for stream testing: temperature, pH, conductivity, dissolved oxygen. One student was responsible for each measurement, to be made at six designated spots along a 300-or-so-yard stretch of the river. A fifth student collected water samples for testing to be done in the classroom; Elizabeth completed the six-person field team. The teacher performed the critical roles of chauffeur and lifeguard. The remaining ten students of the 7th period class, one of five Chemistry sections this year, were back in the ChemRoom completing tests from samples collected by an earlier group: spectrophotometric determinations of various metal ions, turbidity tests, bacterial cultures, and titrations. There was plenty of work to be done. Many things needed to be located and quantified from water that looked perfectly safe and reasonably pure. Two math teachers volunteered to monitor the work of these students; the worst that would happen would be a spilled sample. Matt picked up something that bothered him at Checkpoint #4, a sharp bend in the river where currents swirled and a sneaky deep spot waited to soak anyone shorter that 5980. He was measuring conductivity, and the readings that flashed on his calculator screen seemed odd. “The numbers are too low,” he said to the teacher. He asked to have his testing device checked for flaws. The teacher examined the device; the conductivity meter was operating perfectly. “Hey, Elizabeth,” Matt shouted to the shore, “what was the con-
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Chemistry Everyday for Everyone ductivity at Check-4 last month?” The previous reading was higher, she said. “See?” Matt said, “It’s too low.” What about the conductivity of the other checkpoints?, the teacher asked. “They’re lower, too,” Elizabeth reported. This may be a topic for discussion back in the classroom, the teacher suggested. Overhearing the exchange, Abby, poised at Check-3, adjacent to a fallen tree that nearly crossed the stream completely, said, “Water temp is down, too.” The teacher, wading between Checks #4 and #5, asked Sarah about the dissolved oxygen readings. “D.O. is a little higher, but not much,” said Sarah, who was scrutinizing her readings at checkpoint #5, next to an oak stump. “It’s not a big deal, I don’t think.” Matt wasn’t satisfied yet. “Where’s Chris? Hey Chris!” Matt shouted in a voice that assured the group that we would see no forest creatures on this day. Chris, at checkpoint #1, bellowed an acknowledgment. “What’re you getting for pH’s?” Matt yelped. “Around 8, 8.2,” Chris shouted back. Matt consulted with Elizabeth. The pH was the same as always, more or less, she reported. We’ll have to sort all of this out in class, the teacher commented to Matt. And this is why I’m teaching Chemistry, the teacher thought to himself and smiled. “What are you smiling about?” Sarah asked. “I’m getting paid to force kids to walk in a cold river,” the teacher replied. Just wait until January. At Checkpoint #6, a swampy, wide spot in the river where the current was nearly imperceptible, the group gathered for a traditional group yell before departing the waters. No one was quite sure how this tradition began, but all agreed that it was an appropriate punctuation to thirty minutes of wet and cold science. The teacher asked Chris to briefly explain his earlier System–Surroundings investigation. Matt, upon hearing what Chris really meant by “homework” said, “That makes sense.” Others agreed. Nate, the sample collector, said, “So, if the stream is the system, and we’re testing the stream, aren’t we affecting the data by being in the water? Doesn’t that make us part of the system?” Abby, taking temperature readings, added, “Yeah, when we’re in the stream, don’t our bodies make the water a little warmer?” “Not where I’m standing,” said Matt. “We’re like warm spoons in a really large cup of coffee,” Abby suggested. “More like lukewarm toothpicks in a freezing pool,” Nate said. The teacher said, it was an interesting point, however. Elizabeth, on shore and downstream, missed the entire enlightening discussion. It was repeated for her benefit on the short drive back to the classroom. We have the advantage, at Interlochen, of residing on a 1500-acre campus that rests between two fresh-water lakes. The lakes are connected by the river that the Chemistry classes test at least once per month. The river is a mile from the Chemistry classroom; the short stretch of river that we test is our second classroom and outdoor laboratory. In a fifty-minute class period, a group of six students and the teacher can drive to the river and collect samples and data from several points along the river and return to the classroom. Once in a while we can find a two-hour sliver of time in the weekly schedule, weather permitting, to conduct all our testing on site. All our equipment is portable: a Hach spectrophotometer, Vernier probes, Texas Instruments graphing calculators and CBLs, pencils, and Elizabeth’s water-stained notebook. Occasionally we discover a leaky hip boot, then Nate will assert that we really become part of the system. Every field trip to the stream reveals a concept that has been highlighted in a classroom discussion. Curiously, perhaps, Interlochen Chemistry students are intimately involved with environmental studies throughout the school year, yet they probably would be unable to identify one specific topic or lesson or unit that focused on whatever passes for “Environmental Studies”. When one studies chemistry,
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it is difficult to avoid studying the environment. When the teacher begins a school year by proclaiming, “Chemistry is everywhere,” it is natural to investigate all of these places where chemistry can be found, its principles applied, and the elegance of its laws and theories observed. The next day, Matt was asked to offer his conductivity data and explain why he was troubled by it. Earlier in the fall, the importance of measuring conductivity was explored by Matt and his colleagues. “What does conductivity tell us about the river?” the teacher asked. “What other data could we consult?” Water temperature and dissolved oxygen values could be helpful, if the solubility of substances in the river were important in explaining the decreasing conductivity. The class reviewed the solubility of solids and gases in liquids, and the effect of solvent temperature. “Will the temperature of the river go down more?” one student asked. “We’re in northern Michigan,” Nate said, “and it’s only November. Count on the temperature going way down.” Perhaps Matt’s question will be answered in December’s testing. “I don’t believe I’m saying this,” Matt mumbled, “but I’m kind of looking forward to going back into that stinking creek next month.” The group that conducted tests in the classroom reported its results. A student asked why these particular metal ions—calcium, sodium, magnesium, potassium, iron—were in the river water, and would we find them in any given sample of fresh water. Another student asked if the same ions, in the same concentrations, existed in our drinking water. It was decided that next month, while the field team was avoiding frostbite in the river, the room team would test several drinking water samples from around the campus. Two students offered to talk with the geology teacher and investigate the composition of the soil in the streambed and along the river bank. Nate had been scowling for several minutes, obviously considering some important issue but not yet ready to bring it to the attention of the group. Teachers notice this sort of thing. Nate was asked what was on his mind. “You know, we’re testing this river water in different places, and we’re careful, but the river flows fairly fast and I wonder how good our data is.” A discussion ensued. What was the best way to take samples of river water, and could the group data be better by sampling differently? Nate came to the chalkboard and sketched the stream, making six X-marks to represent the sampling sites. Nate wondered about the total volume of water in the river and how long it took for the water molecules to travel through this portion of the river. It became his project to determine the volume and flow rate of the river, with assistance from the calculus teacher. To bring the group back to the current textbook topic, Chris was asked to describe his system/surroundings example at the stream. Many heads shook in agreement and understanding. One student glanced at the teacher with a look that said, “Why didn’t you think of that a few days ago?” The teacher smiled, and rose to do his job. Kids. Homework was distributed, groans notwithstanding. It would be exceedingly inaccurate to portray this scene as a typical day of Chemistry at Interlochen. It’s not. There are many field trips to the river that are assembly-line activities. We drive silently, slop around in the stream, bark our readings to Elizabeth, she scribbles the numbers into the notebook, we drive silently back to class. Chemistry is not a daily thrill ride. There are many classroom discussions that are, in reality, narratives to a glassy-eyed audience. There are days when we roll up our sleeves and battle a new concept together and at the end of the day we’re not too sure that we haven’t taken a step or two backward. However, there is a great deal to be gained by capturing the moments when science comes alive for students and study-
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Chemistry Everyday for Everyone ing a natural system such as river water offers more of those vivid moments than one might suspect. The class adjourned with plans for several continuing projects: confirming solubility properties of solids and gases, hardness testing of the school’s drinking water supply, investigating the geology of the area, measuring volume and flow of the river. We had begun to connect thermodynamics
with our stream, and future discussions of enthalpy would converge inevitably with the flow of the Little Betsie River. Students gathered their belongings and trooped out of the ChemRoom. Elizabeth took a short detour to stop at the teacher’s desk. “I think,” she said while looking toward the lab bench with its row of water sample bottles, “that I’d like to go in the stream next time.”
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