Density Tower

Have you ever wondered why two objects the same size can have different weights? This is because of density. We can discover the density of something by comparing its mass to its volume. For example if you take a rock and a marshmallow of equal size, which one is denser?


The rock. The rock is heavier for its size. 

Liquids have density too and we can learn more about which liquids are more dense by creating a density tower. 

You will need: 

  • Tall clear glass or vase

  • Food baster or dropper

  • 1/2 cup measure

  • Ingredients: Honey, maple syrup, milk, dish soap, water, oil, rubbing alcohol, baby oil and food colouring (Optional) If you don't have all the items, just try with what you have. 

  • Plastic cups to store measured substances to be added to the density tower.

  1. Begin by measuring 1/2 cup (4 oz) of each substance. It is important to make sure each substance is the same volume so we can compare the density. 

  2. Next add food colouring to some substances if you would like to make the column like a rainbow. 

  3. Now carefully pour the honey into the glass. Make sure the honey doesn't touch the sides. 

  4. Next pour the maple syrup and ensure it doesn't touch the sides either. 

  5.  Now use the food baster to add the milk, soap, water, oil, rubbing alcohol and baby oil. Make sure you rinse between substances. 

  6. Marvel at your awesome density tower. 

What is happening here? 

The lighter liquids (rubbing alcohol, baby oil) are less packed than the heavier liquids (honey, maple syrup) and as a result these will float on top. 

Science Challenge

Try adding some household items to test their density within the column: 

  • peanut, raisins, key, paperclip, bouncy ball. Anything small you can find. 

If the item stays on top of the liquid it means that the liquid is more dense than the solid. If the item sinks it means the solid is more dense than the liquid.