10 Must-Try Halloween Science Experiments.

Halloween Science Experiments

Its October and Halloween will be here soon! Time for creative costumes, spooky decorations, and of course, ALL THE CANDY.  Maximize your Halloween experience with these ten must-try Halloween Science experiments.

You can make actual chemical potions, concoct a batch of zombie virus, spawn some disgusting slime, and bring some ghouls n ghosts back to life for a dance party. We have assembled some of the coolest Halloween-themed science projects for you to try. So get ready to unleash your inner Frankenstein in this list of seriously hair-raising Halloween science projects!

Ooey Gooey Slime

Ooey Gooey Slime

Let’s start with the basics. It just wouldn’t be Halloween without gross, gooey slime.

Are your parents hesitant to let you make slime because it’s too messy? Tell them you just want to create a chemical reaction that will change the molecular structure of glue in order to make it more resistant to flow. It’s all in the name of science! Seriously, though, this is a  chemical reaction where the activators (either the borax, saline solution, or starch) basically change the position of the molecules of the glue to became more viscous, or resistant to flow. What does this even mean? Think about when you pour a glass of water versus when you try to pour ketchup or mustard. Which ones takes longer to pour? It has to do with viscosity.

Let’s get to the slime! 

Fun ways to make Halloween slime. 

Want to make your slime glow in the dark? OF COURSE YOU DO.

Make Glow in the Dark Slime.

Glowing Zombie Virus

Glowing Zombie Virus

We’ve all seen the glowsticks out at night on Halloween and at many parties, but we really don’t think it’s safe to cut one open and play with the ingredients inside them. The chemicals inside the glowsticks can sting and burn, not to mention there is also glass inside of them as well. That’s why it’s so important to keep the plastic tube sealed so you don’t get any of that stuff on yourself.

So instead, let’s keep it safe and make our own glowing water! It’s much safer and produces the same cool effects.

Spooky Lava Lamps

Spooky Lava Lamps

Another kind of eerie, but mesmerizing thing to watch are lava lamps. Have you ever seen one? Wonder what goes on inside and how to make your own? Here’s a super simple guide using the science of density and the unique characteristics of both water and oil molecules.

Spoiler:  The stuff that makes the colored liquid bubbles move is the release of the carbon dioxide and sodium citrate that forms when the Alka Seltzer reacts with the water molecules.

Try it with different colors!



So let’s get to some creepy, crawly Halloween science. You know those gummy worms you see in some Halloween treats? They are cool and slimy (and delicious) on their own, but let’s SCIENCE IT UP a bit more and show you how to make them dance like zombie worms. With just a little baking soda and vinegar you can wow your friends with Frankenworms that move all by themselves. Say it with me IT’S ALIIIIIIVE!!!!

Bring your Frankenworms to life with this experiment.

Pro Tip:

1. To make the gummy worms rise up they need to be super skinny. So ask a grown up to help you slice them up thin.  

2. The longer the worms soak in baking soda, the better this works.


Ok, so the worms don’t ACTUALLY turn to zombies but they are being moved by the carbon dioxide bubbles that are released when you combine the baking soda and vinegar. SUPER CREEPY!

Frankensteins Hands

Frankensteins Hands

Here’s a neat experiment to let a chemical reaction help you create mysterious rising hands. It looks like magic, but it’s science, and you won’t have to use as much of your own carbon dioxide in order to make it happen. Just as with the Frankenworms, let some good old fashioned baking soda and vinegar do the work for you!

Frankensteins Hand Experiment

Here’s a thought: What do you think would happen if you use a highlighter to color the glove and then do this experiment using blacklight? Try it! Or just decorate your Franken-hand to make the results extra spooky.

Dancing Ghosts

Dancing Ghosts

I’m pretty sure ghosts like to come back in order to have dance parties. Wouldn’t that be a great reason to come back? We can help them by using static electricity. Static electricity is an electrical charge that builds up in one area of an object. Like when you go down a slide and suddenly your hair sticks up.  

Now that you know how static works, let’s use that charge to make a dancing ghost! Or several small ones! Create a ghost using some tissue paper and make it stand up all by itself using the buildup of electrical charges! Extra points if you make lots of different shapes dance, like a Frankenstein monster, vampire, or a zombie make up your own choreography to the Monster Mash! If you do, be sure to send us the video.

Make your own dancing ghosts 

Ghost Messages

Ghost Messages

One of my personal favorites is the ghost writing secret message experiment. Here, you use lemon juice to write a message from beyond and then you heat it up in order to reveal the spooky message! It’s scientific invisible ink! This is a cool example of oxidation at work. Applying heat releases the carbon compounds in the dried juice so they come into contact with the air, which turns it a darker color.

Fun fact

Oxidation is the same process that happens when your apple slices turn brown after you cut them and leave them out.

Check out this fun experiment here

Which heat source worked best for you? Make sure you have adult supervision for this one!

Vampires Blood

Vampires Blood

We all know vampires are an important part of Halloween and that they are always looking for blood.

Vampire’s Blood recipe 

This is sure to impress Dracula himself. This can get messy, so make sure you have plenty of paper towels handy. And you might want to wear an apron or something to cover up your clothes. This recipe is pretty realistic so please be cautious and courteous when you use it. Always be responsible when doing science.

If you want to know the scientific components of blood, check out this fun activity that gives you an idea of the different parts of the blood including the red and white blood cells, platelets, and plasma. 

Oozing Pumpkins

Oozing Pumpkins

Halloween is all about the creatively carved pumpkins, AKA Jack-o-Lanterns, on the front porch. You spend a lot of time picking one out, decorating and carving it to perfection. So let’s keep it intact and use it for a cool experiment.

Let’s see if we can make your pumpkin spookier by making it OOZE.

Create your own oozing pumpkin. Play around with your ooze colors!

Dry Ice: The Usual Suspect

Dry Ice: The Usual Suspect

What Halloween Science compilation would be complete without a little dry ice fun? Dry ice is one of the coolest ways to add some spooky atmosphere to any Halloween party or science lab. You can get dry ice from many grocery stores (call ahead and ask if they carry it).

What is dry ice? It is carbon dioxide that has been frozen and compressed so that it is in solid form. They call it dry because it doesn’t melt like water-based ice does. It goes directly from a solid to a gas in a process called sublimation.

So when you see spooky potion and cauldron effects this Halloween, you can see that the creepy fog effect is from the water vapor in the air that condenses into droplets because of this process where carbon dioxide goes from solid to gas. Remember it is about 110 degrees BELOW ZERO so NEVER touch it directly with your hand. Always use safety gloves.

Fun ways to use dry ice this Halloween.


We hope this list of Halloween science experiments has inspired you to try your hand at some spooky potions and gave you cool scientist vibes.  Do you have other suggestions? Did you try and modify any of these experiments? Send us your pics and feedback!

Wishing you a safe and happy Halloween!

Copyright @smorescience. All rights reserved. Do not copy, cite, publish, or distribute this content without permission.

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