All chem students need to be able to understand, produce particle level diagrams of matter representing particle types, phases & temperatures, using different symbols, colors & arrows
Previously students have only had to produce these diagrams as a group, so it is unclear if all students are developing the required skill.
Previously it has been assumed that all students understand and can reproduce these diagrams after the initial week one group activity. However it has been my observation that students don't always feel as comfortable as we expect, which is leading to problems in higher level classes. So an individual quiz was given asking each student to produce a particle diagram of a simple system.
Results from the new quiz showed that while only one student did not produce a satisfactory particle diagram, 50% of the students did not include all the important bits of information in their diagrams, the majority of them only distinguishing a difference in type of particles, but ignoring temperature differences also. It surprised me that so many students are not decerning all the important information
Chemistry students are required to think about the atomic nature of matter, while only being able to see the macroscopic level. To help them, we use particle (atomic) level diagrams that rely on different colors, shapes and lines to represent different types of particles, phases, reactions, and temperatures. These models are used throughout their chemistry courses particularly when systems become too complex to describe concisely in text or formulas. A firm grasp of understanding and drawing these diagrams is important for success in the future. However we never directly assess individual students abilities with these until much later when the diagrams have become much more complicated.