Directed-Discovery of Crystal Structures Using Ball and Stick Models
Summary
In this series of exercises, a kind of reductionist approach is used to direct the students attention to specific characteristics of a variety of ball and stick models. Through a series of leading questions, students must focus on specific relationships and must rationalize these relationships according to the fundamental principles of crystal chemistry and crystallography. In this way, students will simulate and replicate the kinds of questions we would normally ask in our professional careers as mineralogists.
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Context
Audience
This activity is designed for an undergraduate required course in mineralogy and is generally for sophomore or junior level students.
Skills and concepts that students must have mastered
How the activity is situated in the course
This activity is a stand-alone exercise, but is part of a larger volume of classroom and laboratory activities from "Teaching Mineralogy," a workbook published by the Mineralogical Society of America, Brady, J., Mogk, D. W., and Perkins, D., (editors), 1997,406 pp.
Goals
Content/concepts goals for this activity
This exercise provides a series of activities in which students manipulate ball and stick models to discover for themselves the underlying relationships of crystal structures and the principles of crystallography and crystal chemistry.
Higher order thinking skills goals for this activity
Other skills goals for this activity
This activity should also improve upon students' ability to write.
Description of the activity/assignment
In this series of exercises, a kind of reductionist approach is used to direct the students attention to specific characteristics of a variety of ball and stick models. Through a series of leading questions, students must focus on specific relationships and must rationalize these relationships according to the fundamental principles of crystal chemistry and crystallography. In this way, students will simulate and replicate the kinds of questions we would normally ask in our professional careers as mineralogists. This approach also addresses other major recommendations from Project 2061: start with questions about nature, and concentrate on the collection and use of evidence. Other questions ask students to make connections to basic chemistry (e.g. bond types, relative strength of bonds, bond angles), determinative mineralogy (most likely place to develop cleavage), analytical techniques (e.g. preferred orientations for X-ray analysis), and so on. The final reflection questions will allow students to "discover" Pauling's Rules, a much more effective learning strategy than simple memorization of these rules (commonly with little or no understanding on the part of the students).
Determining whether students have met the goals
Students have met the goals of this activity if they answer the leading and summary questions (in the download) accurately and thoroughly.
More information about assessment tools and techniques.Teaching materials and tips
Other Materials
- Assignment description, hand outs, and instructor's notes. (Microsoft Word 35kB May9 08)
- Assignment description, hand outs, and instructor's notes. (Acrobat (PDF) 46kB May9 08)
Supporting references/URLs
Brady, J., Mogk, D. W., and Perkins, D., (editors), 1997, Teaching Mineralogy, a workbook published by the Mineralogical Society of America, 406 pp.
Mineralogical Society of America - become a member today!
Mineralogical Society of America - become a member today!