In this 2 day inquiry-based lesson, students design an experiment and test coatings to determine which would prevent the corrosion of shiny, new pennies the best! It can be edited to provide more or less scaffolding depending on how well your students can design their own experiment! It should be taught after learning the differences between physical and chemical changes.
After students analyze 3 pennies at various stages of corrosion, they are challenged to develop a plan to prevent the corrosion of pennies (engineering). Given some materials, students design and carry out their experiment during day one. On day two (works best over the weekend!), they collect data on their coatings and determine which worked the best and why. In the conclusions, students are asked to reflect on the experiment as to what worked, what didn't, what they would revise, why they used a "control penny" and the costs and benefits to each of their coats to relate it to the real engineering process! My students loved this lab! It works best when vinegar is used and the pennies are completely submerged and soaked overnight. It's a great introductory lesson on how to design an experiment as well!
It aligns with the following NGSS Next Generation Science Standards:
MS-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine
if a chemical reaction has occurred.
MS-ETS1-1. Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution,
taking into account relevant scientific principles and potential impacts on people and the natural environment
that may limit possible solutions.