Topic: Materials

Exploring Density




To see the effect of density with different liquids.


  • Glass cylinder or clear drinking glass
  • Honey
  • Liquid dishwashing soap or detergent
  • Corn syrup
  • Water
  • Cooking oil
  • Rubbing alcohol (or other) *Request permission from an adult
  • Food colouring



Slowly pour the honey into the centre of the glass or cylinder until it has reached a 1-2 cm thick layer. Take care not to let the honey touch the sides of the glass!


Pour a few tablespoons of the corn syrup into a small bowl and place 1-2 drops of food colouring into the bowl as well, mixing them to achieve a bright colour. Then carefully pour this bright corn syrup into the glass or cylinder, again taking care not to let it touch the sides. There should now be two layers!


Next slowly pour a layer of dishwashing liquid into the glass or cylinder, to the same 1-2 cm thickness. Your glass should be almost halfway full now.


The next level will be water. But this time, instead of pouring it into the centre of the glass or cylinder, you will need to have it in a jug with a lip to pour it very slowly down the side of the glass until 1-2 cm thick. This is to make sure the layers are not broken into.


The cooking oil comes next. Just like the water before, carefully pour the oil down the side of the glass until it reaches a 1-2 cm thick layer.


Finally, consult an adult to see if they can help you to add an optional layer – rubbing alcohol or other kind of alcohol. The same technique should be used to complete this layer.


You should now have a 5 or 6 layer density column! 

But why did none of the layers mix together? Well, you may already know that oil and water don’t mix, but did you know it was due to their different densities? Density is a property of a substance, which tells you how packed it is. If a substance is very dense, it has many many molecules packed into a small amount of space, which makes it heavier. But if a substance has a lesser density, with fewer molecules packed in that space, it is lighter even if it takes up the same amount of space!

This is why we put the honey at the bottom of the glass or cylinder. Honey has the highest density (heavier) than the other ingredients. And the order that we put each next level in, is the order that the ingredients are less and less dense.