Density experiment – pirate themed

I’ve got another fun pirate themed activity today, this time demonstrating density. Density is quite a hard concept to grasp but this is a really nice introduction and full of little wow moments.

Just the fact that the oil sits on the water is quite fun. You could put blue water and oil into a plastic bottle and shake around to really get the effect and show how oil and water don’t mix.

density experiment

What you need

Empty bottle or jar


Oil – we used very cheap vegetable oil.

Pirate objects to test


Half fill your container with water, then add some oil. What do you notice?

Carefully drop your objects into the jar, what happens? Can you find something to float on each layer?

density experiment


We found our pirate coin sank right to the bottom, the beads floated on the water, but not the oil and the cork floated on the oil.


density experiment

See this post for a full explanation about density.

Extension tasks

Can you put your hand into the jar? What do you notice about the oil and water? – We found that the oil felt warm and the water cold, there was a noticable difference between the layers. Why do you think this is?

Related posts

Magic Density

What is density?


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