Chemistry 123, January 1995 (Hanson) The following are my reflections on Chemistry 123 as presented in 1995. This course has seen a major transition over the past few years. Course Description Chemistry 123, Chemical Structure, is an introduction to the structure and, to a limited extent, the reactivity of atoms and molecules. The course is designed to be a bridging course between Chemistry 121 and Chemistry 126. However, it is also conceivable that the course in its current form (were it approved) could be appropriate for non-lab general education credit and possibly CWC in the format used in 1995. Course Material The interim was divided into two parts atoms for the first two weeks and molecules for the second two weeks. A calendar is attached. Although Zumdahl's book was used as background and reference, little direct reading assignment was made from that book. Instead, we started out with Data-Driven Chemistry focusing first on the hydrogen atom (5 days) and then on atoms with more than one electron (3 days). A description of Data-Driven Chemistry is attached, including the actual "data" presented along with questions asked an instructor guide is also available. For the second half of the interim, we spent one day working on ionic compounds and then focused on molecules, using my Molecular Origami as a guide. The idea here was to build a set of 120 precision models (300,000,000:1 scale) that students could use for the rest of the interim as a database. A list of these models is also attached, along with the data for one- and two-dimensional models. Each student made three or four 3-D models. Questions asked included: How can we predict a molecule's shape from its Lewis structure (or, even simpler, from a "sigma" structure, which has no double bonds marked)? Why are the molecules the basic shapes that they are? What constitutes a bond? Why might some bonds be longer and some shorter? Why might some angles be smaller and some larger? How might structure relate to reactivity, especially in terms of acids and bases? In discussing these questions, we tapped into localized bond theory, VESPR theory, and, finally, molecular orbital theory. Course Mechanics Students met each day from 1:30 3:30. For at least the first 15 minutes sometime up to an hour I introduced the topic of the day. Then students broke into five groups of 9 11 students each for about an hour to discuss the data. Finally, students returned to Sc378 for a wrap-ip discussion of points that were still not clear. The five assistants had been primed for the discussion in a lunchtime meeting with me from 1:00 1:25 each day for the first two weeks. We discussed group dynamics and interesting or important aspects of the data. Every other day for the first two weeks students wrote essays desccribing their personal "model" of the atoms. These essays grew longer and more sophisticated as time went on and more data were included. Nonetheless, I found it possible to read and comment upon all 50 of them in about 2 3 hours. (These essays were due at 10:00 AM and returned that afternoon. However, it probably would have been OK had they been returned a day later, as they were only due every other day.) On Friday, January 13th, students wrote an exam consisting of three questions and about five sheets of blank paper. The exam is attached. Overall, these exams were a great joy to read. Scores ranged from 35 110, with an average of 88%. (All exept one student got C or better; that student turned in only one essay prior to the exam and left St. Olaf the next semester.) During the second half of the interim, homework consisted of answering a set of questions, one per day, relating to the molecular database as a whole. These assignments are also attached. Course and Student Evaluation The final exam consisted of traditional questions relating to atoms and molecules. Grading was based on the following distribution of points: homework (75), participation (25), midterm exam (100), and final exam (200). Evaluation of the course was carried out using the Gold form with added questions. (See attached.) In general, the group was satisfied with their experience (questions 32, 46, 47, and 48). They liked the essays (#30), the time of 1:30 3:30 (#38), and the breaking into small groups for discussion (#39), although they had mixed feelings about their group leaders' abilities (#42). In addition, they felt the models were helpful at least to a certain extent (#34), and 60% would have been willing to buy Molecular Origami for about $20 (#36; 8 of 48 respondents disagreed or disagreed strongly with that idea). Selected anecdotal comments are included here: While it was disturbing to have so little reliance on the textbook, I feel I probably learned more from not using it. Instead of reading information we figured it out for ourselves. I really liked [the] data sheets and the hands on approach both with atoms and molecules...Overall I really enjoyed the class and learned a lot. The first two weeks were very interesting. I loved the way it was taught; even I could comprehend it. The second half was a lot harder for some reason. It was just more complex. More time on it would have been great. Writing an essay every other day was a fabulous way to learn. I would have liked to continue in this manner all month long....I learned much more in the large group setting than in the small group. My TA often didn't seem very knowledgeable in the subject area and left us confused. This was very frustrating and seemed a waste of time. The essays were very helpful in forcing me to learn the material well Kind of similar to "reteaching" what we had learned in class. It was also great to see actual data and analyze that to learn various theories. I really enjoyed the class size [50] and having teaching assistants available for help outside of class. Writing the essays worked well for learning about atoms. Making the models were a good idea. They helped a lot....The T.A.'s didn't really seem to know what they were doing and often times ended up showing us the way they had learned it and not the way we were supposed to learn it. It would have been nice to have had a book that coincided with what we were learning. I definitely would have paid $20 for a book of models and questions. I began to get frustrated when some things that we learned were right one day and completely wrong the next day. It confused me at times but made me a critical thinker and improved these skills. The course provided me with a much better picture of atoms and molecules and how they bond than I would have gotten in 125 in a very organized way which built on other models to explain them better. I think the teaching assistants need to be reviewed more carefully in terms of the depth of their knowledge and communication skills. It was also a bit annoying at first to keep changing our models and made me a bit skeptical as to whether or not what I was learning would only need to be changed. My teaching assistant had NO CLUE what she was doing!...It would have helped to be able to use the book more. It was confusing to go into groups first and then discuss later because we were told different things sometimes in the groups and then learn the right answer later. It might be better to discuss the material first and then break into groups. The format of the course was extremely helpful. A short intro to the material, then small group discussion and hands-on work, with a large group summary was excellent! I feel I understand this better than I would have just through lecture, and it was more interesting this way, too. Especially within the sciences, two clear-cut ways to learn exist. For so long science has been stuck in a mathematical mode i.e., we tell you facts, you memorize facts, you reguritate facts on tests. This works well for many students and is a good method. However, this class was almost perfectly suited to the other kind of student (myself). The class was theoretical and visual and provoked intense thought. It is of paramount importance to continue and broaden this style of teaching in science. This was the best class I have had at St. Olaf and I thoroughly enjoyed it. Also Chemistry 121 was far too much like Chemistry 125 and not enough like 123 the classes should be divided distinctly not one taught one way and the other half and half. I have more to say...signed... Don't make the final worth 50%! Chemistry 123 interim course evaluation supplemental questions. January, 1995, Professor R. Hanson 03-1230-025 (1) strongly disagree (2) disagree (3) disagree somewhat (4) agree somewhat (5) agree (6) strongly agree median/mean indicated in italics Atoms: First two weeks 29. Analyzing "data" was effective in helping me learn about atoms. (5.50/5.21) 30. The essays were effective in helping me learn about atoms. (5.61/5.38) 31. It was disturbing to have so little reliance on the textbook. (3.96/3.81) 32. I feel that I learned what I needed to know about atoms. (5.23/5.17) 33. I wish I had learned about atoms this way in my high school chemistry course. (Leave blank if not applicable.) (4.89/4.51) Molecules: Second two weeks 34. The 300,000,000:1 scale models were effective in helping me learn about the structure of molecules. (4.85/4.77) 35. Analyzing the slight variations in molecular structures presented by the models helped me learn about bonding. (4.79/4.71) 36. I would have been willing to spend $20 to buy a book of models with associated questions and discussion relating to bonding. (4.00/3.94) 37. I wish I had learned about molecules this way in my high school chemistry course. (Leave blank if not applicable.) (4.91/4.64) General Questions 38. The 1:30 3:30 time slot worked well for me. (5.05/4.83) 39. Breaking into small groups was a good idea. (5.21/4.98) 40. My group leader was effective in facilitating discussion. (4.57/4.42) 41. My group leader was available outside of the 1:30 3:30 time period (4.92/4.73) 42. My group leader was knowledgeable in the subject area. (4.15/4.12) 43. It was disturbing to have so little reliance on the textbook. (3.86/3.65) 44. It was disturbing to work with theories which seemed in conflict with those of the textbook author. (4.25/4.02) 45. It would have been better to have this material in Chemistry 121 and reserve Chemistry 123 for a more in-depth look at equilibrium calculations. (2.58/2.65) 46. I am satisfied with my choice of Chemistry 121/123 instead of Chemistry 125. (5.58/5.19) 47. I would recommend the Chemistry 121/123 sequence instead of Chemistry 125 to others in my situation. (5.29/4.98) 48. The workload in Chemistry 123, for an interim course, was: (1) too little (2) about right (3) too much (2.00/2.00) 49. My grade in Chemistry 121 was: (1) C or below (2) C or C+ (3) B , B, or B+ (4) A , A, or A+ (2.88/2.88) 50. I expect my grade in Chemistry 123 will be: (1) C or below (2) C or C+ (3) B , B, or B+ (4) A , A, or A+ (5) no idea (3.46/3.46, excluding 5)