Suggested Grades



Students will see the effects of density when a variety of liquids are poured on top of each other and when a variety of objects are dropped into each one.


  • at least 7 small clear plastic cups
  • light corn syrup
  • lamp oil
  • milk
  • water
  • a piece of cork
  • a piece of a candle
  • a piece of metal
    *Each object should also be the same size as each other.


Do this activity as a demonstration or in class groups.

Part 1

  • Pour liquids in each glass in the order shown below. Pour out a glass of each liquid combination, so you will have 3 filled glasses in total.
    • 1) corn syrup, milk, oil
    • 2) milk, oil, corn syrup
    • 3) oil, corn syrup, milk
  • What happened? Draw your observations. Why did this happen? Organize the liquids from most to least dense.(You should be able to some layers clearly because each liquid has a different density. If the layers combine then the top layer has the heavier density than the one that it was poured on top of.)
  • Try the experiment with other liquids.

Part 2

  • Pour out a little of each liquid in separate glasses. Include a glass with a little water in it. So, you will have 4 glasses of liquids in total.
  • Try dropping a piece of cork, into the middle of each liquid. In which liquids did it sink? In which liquids did it float? Record.
  • Fish out the cork, or use a new piece that is equal in size and weight, and repeat the process with the pieces of candle and metal.
  • Which objects floated the most? Which objects sank the most? Organize the objects for most to least dense.
  • Try the experiment with other liquids.