Density Column (3 Layers) Sink or Float

Good evening scientists. Today while eating lunch my little scientist mentioned that ice always floats. This led us on a path of discovery. I told him that he was right it always floats on water, but that it doesn’t necessarily always float. This got my husband’s attention as well as little scientist. Next we headed to our kitchen to try out a new experiment.

MaterialsDensity Column Sink or Float (2)

Clear Glass, Cup, Jar or Vase

Light Corn Syrup

Water Bottle or Water (Food Coloring Optional)

Vegetable Oil

Ice Cube


Cherry Tomato


Optional: Other small items such as plastic tops (thickness of the plastic affects where they end up in the column), chocolate chips, small candies or other small objects.


  1. Fill fill a clear vase about 1/3 of the way up with light corn syrup.Density Column Sink or Float (7)
  2. We added one drop of pink food coloring to our water bottle. Use the water to continue filling the vase until 2/3 of the way full. Density Column Sink or Float (14)
  3. Fill the vase with vegetable oil stopping a few centimetres from the top.
  4. Now that you have your 3 layers in your density column you and your little scientist get to play with density by seeing what sinks or floats on the layers. To get your started: Cork will float on the vegetable oil, Ice sinks and floats on the water (ice from a bag) strangely some of our ice from our ice-maker teetered in the middle of the vegetable oil and as it melted would melt and water droplets would sink to the water layer. A cherry tomato sinks down and float on the corn syrup layer. A rock will sink to the bottom of the glass.

Talking Points

This activity was a great way to show that both liquids and solids have density. Density is how much mater (stuff) is packed into an area. The more stuff the more dense the object, and the less stuff the less dense. Our density column is layered in three layers from top to bottom it is least dense to most dense: vegetable oil –> water –> light corn syrup.

With objects from least dense to most dense we found: Cork & Some Plastic Tops (We tested an apple juice bottle cap and it floated) –> Vegetable Oil –> Ice & Some Plastic Caps (Our water bottle cap sank to just above the water)–>Water –> Cherry Tomato –> Light Corn Syrup –> Rock

Extended Learning: Try out these other related investigations

Sink or Float (41)
Sink or Float
Density in a Jar (29)
Density in a Jar (6 Layers)

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