5 Fun Halloween Science Experiments for Kids


Halloween is the best time of year to turn your kitchen into a science lab and have fun with lots of experiments. The more gooey, slimy and spooky the better! From glowing monster slime, to screechy sounds, here’s 5 Fun Halloween Science Experiments for Kids.

1. Glowing Monster Slime

slime1This is definitely, by far, our favourite Halloween experiment –  just look at the photos if you need any convincing!

You will need…

  • Two small bowls or cups
  • One large bowl
  • PVA glue (white or clear is you can get it)
  • Fluorescent paint (you can get non-toxic fluorescent paint in most craft shops)
  • Food colouring (optional)
  • Something to stir or mix with
  • Borax*

*You can pick up the borax powder in your local chemist (See note below)

What you do… 

  1. To the first cup add half a cup of fluorescent paint and half a cup of PVA glue and mix well.
  2. In the other cup add half a teaspoon of borax powder to one cup of water and mix well until all the powder is dissolved!
  3. Now for the fun bit… pour the glue mixture into the bowl then add the borax solution, mixing all the time. After a while you can use your hands to mix and mould until you have one big lump of slime!
  4. You can store your slime in a ziplock bag or clean jar, it lasts a very long time once you do not let it dry out.
  5. If you have a UV light (black light) you can make this experiment even more fun by checking out how your slime glows in the dark once the lights go out and the UV light is turned on.


So what is happening?…

Congratulation… you have just experimented with polymers!! In simple terms a polymer is a substance made up of lots of molecules arranged in long chains.

If you imagine that the glue is like cooked spaghetti, it slides and slips around the place quite easily.  When we add the borax to the glue it causes some of the molecules in the glue to stick together making the glue more rubbery and less liquid!  Imagine if you took those strands of spaghetti and tied them together in places, the strands would not be able to slip and slide around nearly as much! The borax and glue mixture is just like your knotted spaghetti!

*Where can I get Borax powder?

In Ireland you need to buy Borax powder in a pharmacy.  The production is a little erratic and the larger volumes are no longer available!  You should be able to get this 100g tub in any pharmacy and it costs between €2 and €3.

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