This resource introduces the concept of chemical changes through a practical example of rusting. It guides learners to observe the transformation of a shiny nail into a rusty one, highlighting key concepts such as reactants and products. Students are encouraged to use macroscopic evidence to identify signs of chemical changes, such as unexpected color changes, gas production, temperature changes, odor, and light production. The document includes a 5-point checklist summarizing these signs and encourages critical thinking by prompting students to analyze their observations and understand the underlying chemical processes.