Gas laws can provide an opportunity to integrate several important ideas in a traditional chemistry course: a particle-level understanding of matter, relatable phenomena, and a sense of how scientific principles are developed over time. In OpenSciEd Chemistry, this integration is a core design principle across all units. Students are always actively developing scientific principles at both a macroscopic and particle-level scale over time, in the context of relatable phenomena. A particle-level understanding of matter, including gases, is also so central to the course. It is built and used across multiple units, with a particular emphasis in C.1 Thermodynamic in Earth’s Systems, as students reconstruct and iterate on the middle school particle model first developed in OpenSciEd Middle School Units 6.1 Light & Matter and 6.2 Thermal Energy. However, students also begin to dig more into the behavior of matter at the particle level. Students consider changes in volume and density in C.1 Thermodynamic in Earth’s Systems. In C.2 Structure & Properties of Matter, students model gas behavior in the storm clouds responsible for lightning and in C.4 Chemical Reactions in our World. they develop an understanding of gases dissolving into (and escaping from) water. 

Fundamental gas laws are useful for describing particular phenomena in particular contexts, which is why in C.5 Energy from Chemical & Nuclear Processes, students analyze data of pressure, volume, and temperature to make sense of the compression stroke in diesel engines using the combined gas law. The combined gas law was chosen as a particular point of emphasis in Lesson 3 because it is the most useful to explain the phenomena at hand. However, guidance is provided on how students can be motivated to think about the number of particles in the system to help develop the ideal gas law. If it is necessary to name other gas laws, these could be introduced alongside students’ development of pieces of the combined gas law in Lessons 2 and 3.

References

American Chemical Society. (2018). ACS Guidelines and recommendations for teaching middle and high school chemistry. www.acs.org /mshsguidelines

National Governors Association Center for Best Practices and Council of Chief State School Officers. (2010). Common core state standards. https://www.thecorestandards.org/

National Research Council. (2012).  A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. The National Academies Press. https://doi.org/10.17226/13165

NGSS Lead States. (2013). Next generation science standards: For states, by states. The National Academies Press.