This feature is a molecular model from Molecular Workbench-MW (a software engine that computes and visualizes the motion of ensembles of particles in real time, in both 2D and 3D). MW models dynamically represent the microscopic structure of matter and response to userís actions like heating, cooling, adding pressure, addding and reactants or other changes of the chemical system and conditions. For example, students can observe the typical motion of the particles in the liquid state, interact with the system to heat or cool it, and observe the changes.
Throughout the project, the students interact with molecular models of the solid, liquid and gaseous states. In each case, they compare the static and the dynamic molecular models, run the model and complete interactive tasks planned to focus on its specific features, and write their reflections on the interaction with the model afterwards. Instructions come with the model and are easy to read and follow.
The Rationale Behind the Feature (Specific Design Principle):
The idea behind this feature is to help students see and understand molecular structure and its dynamic behavior in each of the different state of matter. Dynamic molecular models add the real-time motion aspect to the static molecular models usually presented as pictures in books. Using computerized environments like MW, students can explore the causes of phenomena at the atomic level and can investigate these causes by direct interaction.
Context of Use:
This feature is part of a TELS project called: Phases of Matter & Phase Change (#16999) It was developed by Dalit Levy at the Concord Consortium.
Evidence about how this feature was accepted in class runs will be uploaded soon.
Q. Xie and R. Tinker, Molecular Dynamics Simulations of Chemical Reactions for Use in Education, Journal of Chemical Education, 83, 77-83 (2006) A. Pallant and R. Tinker, Reasoning with Atomic-Scale Molecular Dynamic Models, Journal of Science Education and Technology, 13, 51-66 (2004) MW website: mw.concord.org