In this in-class activity, students are broken up into teams of 4, which are then sub-divided into two teams of two for the building of the structures. The activity makes use of the ICE Solid State Model kits, and each group should have their own full kit.
The activity has 6 sets of structures for the teams to build; depending on the length of your class, you could have each team build all six sets OR have each team build one of the six sets to then share with the rest of the class.
A - HCP and CCP
B - Primitive cubic and CsCl
C - NaCl (FCC) and NaCl (along the body-diagonal, shows the ABCA pattern well)
D - Fluorite and Anti-Fluorite
E - Zinc Blende and Wurtzite
F - Diamond and Graphite
There are related questions to answer for each of the structures built.
A student will be able to recognize packing patterns and unit cells within solid state models.
A student will gain an understanding of packing/hole filling in ionic structures through classic solid state examples (NaCl, CaF2, ZnS).
Institute for Chemical Education (ICE) Solid State Model Kits for each team.
I have run this as a dry lab and had each team build all six sets of structures; this usually takes the full 2.5 hour time block.
I used it as an in-class activity this year and had each of my six teams build one set of the structures to share with the rest of the class. This way they got experience building the models (for hands-on learners) but can use the models built by others to answer the questions. I had the models available after class for students to come back to, if necessary, to answer any remaining questions before the assignment was due.
The spacer rods seem to give the most problems in constructing the models (graphite, diamond, ZnS), so try to be sure that they are pre-cut to the proper length before running the activity.
Answers are evaluated for correctness. Please see key for answers.
Students always seem to have difficulty drawing the 3-D structures in 2-D.
They generally do very well on the assignment. Misconceptions typically arise in the number of nearest neighbors for the different ions and in the fluorite structure (since the ions are not in their typical locations).