Mrs. Tischio and her son, Cody, create a liquid stack rainbow using liquids with different densitities. Denser liquids sink to the bottom, while the lighter liquids sit on top. But be careful! some liquids will mix if they are put together too fast.
I watched this show on Disney+ the other day with my third grader, and thought it was a fascinating extension to our lessons on selection and how adaptations can be changed over time by environment or human influence. While this link will take you only to the description, the show (44 minutes) can be found on Disney+ or National Geographic.