How Can I Smell Things from a Distance?
In order to contextualize core ideas about the nature of matter, this unit focuses on the everyday life experience of smelling odors whether close to or far from one’s nose. As students investigate this and other phenomena, they develop models of how people smell odors, and use their models to explain and predict what happens in various scenarios. Rather than simply accepting a particle model (that matter is comprised of molecules, which are comprised of atoms), students come to understand this core science idea over time as the only way to explain that air can be compressed, expanded, added to and subtracted from a container. Students then use the particle model to explain why substances have different properties, and to explain the behavior of particles in each state of matter and at a substance’s melting and boiling points during phase change, including the relationship between the movement of molecules and temperature. Students’ model of matter, which is represented both as a drawing and a written explanation, represents a conceptual understanding that “all matter is made of particles in constant motion,” a concept revisited in future IQWST units in physics, chemistry, life science, and Earth science and central to all future science learning.