Daffy Density - Experiment 16

All materials have characteristic densities. As long as the materials do not mix or react, the less dense materials will float on top of the more dense ones. This activity can be done as a lab or demonstration, using 4 solids and 6 liquids. It creates colorful, layered rows.

Materials Substitutions
graduated cylinder large vase (cylindrical) or large test tube
ethanol rubbing alcohol (green)
Dawn™ dishwashing detergent liquid dishwashing detergent
dark corn syrup
vegetable oil
glycerine
water
food coloring (red and green)
Optional Solids:
cork stopper fishing cork bobber
solid rubber stopper rubber Superball or jacks ball
1 small block of oak wood
1 small piece of lead a lead sinker

Procedure

  1. Slowly pour in order the following liquids into a graduated cylinder:
    • dark Karo syrup (pour without touching the container sides)
    • glycerine
    • Dawn dishwashing liquid (blue)
    • water (with red food coloring added)
    • vegetable oil (yellow)
    • rubbing alcohol (with green food coloring added)

    Pour carefully so that layers will form. (See illustration).

  2. Add small samples of the solids listed above in the following order:
    lead, rubber, oak, cork. Try to avoid mixing the layers.

exp17

Teacher’s Notes

  1. Other solids may be added and their relative densities determined. Suggested solids include:
    • a new penny (>1986)
    • candle wax
    • a wooden toothpick
    • a small block of pine
    • an ice cube
  2. Students can complete this as a laboratory exercise. If given some densities as ‘knowns’, they should be able to set approximate ranges for the other materials.

Disposal
All liquids can be poured down the sink. Solids may be reused.