Density Tower: Layering Liquids

Tall clear glass or graduated cylinder Honey Corn syrup Maple syrup Whole milk Dish soap Water (dyed blue) Vegetable oil Rubbing alcohol (dyed red) Small objects: grape, cork, plastic bead, metal bolt

1. Slowly pour each liquid into the glass in order from most dense to least dense: honey, corn syrup, maple syrup, dish soap, milk, water, vegetable oil, rubbing alcohol. 2. Pour each liquid slowly over the back of a spoon to minimize mixing. 3. Wait 2 minutes between each layer for settling. 4. Observe layer boundaries. 5. Gently drop small objects one at a time and record which layer they float on. 6. Leave the tower undisturbed for 24 hours and observe again.

All 8 liquids formed distinct layers initially. Honey and corn syrup boundary was the hardest to see (similar color). Maple syrup and dish soap mixed slightly at their boundary. After 24 hours, milk had partially mixed with water layer — boundary became cloudy. All other layers remained distinct. Grape sank to the corn syrup layer. Cork floated on rubbing alcohol. Metal bolt sank to the bottom (honey). Plastic bead settled on the water/oil boundary.

Classic density demonstration works reliably. The milk instability over 24 hours is worth discussing — it's a colloid, not a true solution. Key teaching moment: density is a property of the substance, not the amount. Students love predicting where objects will settle.