Creepy density demonstration for Halloween

Welcome to our Halloween density demonstration. Density sounds complicated, but it is a very cool concept to explore, leading to many fun, creative science opportunities.

The image below shows a traditional density jar made with honey, golden syrup, washing-up liquid, water and vegetable oil.

I adapted the activity slightly to make a creepy Halloween version!

What you need to make a density tower

Treacle

Tall glass or jar
Golden Syrup
Water
Food colouring
Vegetable Oil
Small items to test for floating

Density Tower Instructions

Pour each liquid into the glass slowly, starting with the treacle, then the golden syrup, followed by the water with added food colouring and finally the vegetable oil.

Drop a few small items into the jar and watch to see which layer they float on.

In the image above, you can see a plastic bug floating on top, a LEGO brick floating on the water, and a paper clip floating on the treacle. Why do they do this?

Why does a density tower work?

Each liquid has a different density. The more dense a liquid is, the heavier it is. In the demonstration above, the most dense liquids are on the bottom and the least dense at the top.

Objects and liquids float on liquids of a higher density and sink through liquids of lower density. The LEGO brick falls through the oil but floats on the water. The plastic bug floating on the oil is less dense than all the liquids used.

For a complete explanation, see my floating and density post.

If you liked this spooky activity, you'll love my collection of Halloween science experiments, including making fake blood, spooky potions and lots more creepy science for kids!

Don't forget to check out our other fun science activities for children, too!

You might also like my book Gross Science!

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Last Updated on October 3, 2024 by Emma Vanstone