30 Halloween Science Experiments for Classrooms

Halloween is the perfect occasion to try some spooky, creepy, candy-centered Halloween science experiments! We’ve rounded up 30 hands-on Halloween science experiments that explore concepts such as the scientific method, osmosis, exothermic reactions, and more.

You’ll only need simple supplies for most of these Halloween science experiments, so any teacher or family can head out to learn about chemistry, biology, physics, and more. To make it even easier to find the right science activities, we’ve rated each of our Halloween science experiments for difficulty:

Easy: Simple, short activities you can do with little or no prep needed.
Medium: These activities take a little longer or require a few extra supplies but are still fairly simple.
Advanced: Activities that require more unusual supplies or complex skills.

30 Frightening Halloween Science Experiments

We Are Teachers slime pulling — We Are Teachers

1. Brew up your own slime

Chances are good your students already love making and playing with slime. Turn the fun into an experiment by changing the ingredients to create slime with a variety of properties—from magnetic to glow-in-the-dark!

(Difficulty: Medium)

Try it: How To Make Slime

clear plastic gloves filled with plastic halloween toys and frozen water — Happy Hooligans

2. Experiment with this haunted Halloween hand melt

This fun activity will teach your students about the effect of salt on frozen water. They will make observations as the creepy hands melt and colorful Halloween toys emerge from the slush.

(Difficulty: Easy)

Try it: Haunted Halloween Hand Melt

3. Build a spooky hand

Using paper, straws, yarn, and tape, create a moveable hand that replicates the movement of a human hand. Add a spooky touch by making the tips of the fingers pointy.

(Difficulty: Advanced)

4. Test sinking & floating

Determine if a pumpkin sinks or floats in water by conducting an experiment. Test other elements of the pumpkin separately, such as the stem, seeds, and pulp.

(Difficulty: Easy)

Try it: Pumpkin Experiment

young girl with science glasses looking at vials of candy potions- Halloween science experiments — Housing a Forest

5. Brew up some candy potions

Let your little scientists loose as they play Mad Scientist … mixing, dumping, shaking, pouring, and experimenting to create their own magic potions from Halloween candy.

(Difficulty: Easy)

Try it: Candy Potions

6. Monitor a decomposing pumpkin

Decomposition, or rotting, is the process by which organic substances are broken down after death. Eventually, decomposition breaks organic matter down so that it becomes part of the soil again. And what better tool for this lesson than an old jack-o’-lantern?

(Difficulty: Easy)

Try it: Pumpkin Decomposition Experiment

Jack O Lantern Coding — Naomi Meredith—The Elementary STEM Coach

7. Code robots to create a jack-o’-lantern

Print different pictures of jack-o’-lantern faces individually on cards. Code a moveable robot to collect pieces that will complete the jack-o’-lantern face.

(Difficulty: Medium)

Try it: Jack-o’-Lantern Robot

8. Explore the math inside a candy bar

By using the scientific method, determine the density, volume, and mass inside different candy bars.

(Difficulty: Advanced)

Try it: Candy Bar Density Lab

Launch a Flying Bat- Halloween science experiments — Buggy and Buddy

9. Launch a flying Bat

Create a paper tube that fits around a straw and close off one of the ends. Draw or print out a bat template and attach it to the paper tube. Blow through the straw and watch the bat fly!

(Difficulty: Medium)

Try it: Flying Bat Straw Rockets

a child's fingers squeezing a ghost shaped Peep in the mouth of a glass bottle- Halloween science experiments — Housing a Forest

10. Create an exploding Peeps ghost geyser

Exploding? Say no more! Your students will be enthralled as they watch ghost-shaped Peeps transform when they’re placed in the microwave.

(Difficulty: Easy)

Try it: Exploding Peep Geysers

11. Remove the “M” from M&Ms

Observe how M&M’s have different chemical structures that make the colors dissolve in water, but the letters stay intact.

(Difficulty: Easy)

Try it: Floating M M&M Candy Science Experiment

Test Candy Acidity- Halloween science experiments — Our Family Code

12. Test candy acidity

A simple experiment to test whether candy has acid in it. All you need are sour Skittles, water, and baking soda. If the candy has acid, the mixture will bubble and fizz when the baking soda is added.

(Difficulty: Medium)

Try it: Candy pH Science Activity

13. Make your own candy vending machine

There are a lot of variations of this project on YouTube from Hack Room, but it’s sure to challenge students’ engineering and planning skills.

(Difficulty: Advanced)

A clear glass of fizzy liquid with dancing gummy worms inside — Playdough to Plato

Make an Oozing Monster- Halloween science experiments — The Kitchen Pantry Scientist

15. Make an oozing monster

Create a monster face on the outside of a plastic water bottle. Mix together glue, borax, baking soda, vinegar, and food coloring and add to the bottle. Watch how the foaming mixture leaks out of the monster’s head.

(Difficulty: Medium)

Try it: Oozing Monster Heads

16. Inflate pumpkin balloons

Using a permanent marker, draw a face on an orange balloon. Fill the balloon with baking soda and attach to a water bottle filled with vinegar. Watch the pumpkin grow bigger!

(Difficulty: Easy)

17. Instigate a fizzy eruption

This experiment is a crowd-pleasing classic! Your students will love creating geysers from Diet Coke and Mentos as they learn about chemical reactions. Definitely an outdoor activity!

(Difficulty: Easy)

four regular size gummy bears on top of four supersized gummy bears- Halloween science experiments — Playdough to Plato

18. Supersize some gummy bears

Little ones will love this Alice in Wonderland–style experiment. Using water, salt, and gummy bears, your students will learn about the process of osmosis.

(Difficulty: Medium)

Try it: Growing Gummy Bear Science

2 experiments laid out for students with glass jars filled with different liquids and halloween candies on the side — Lemon Lime Adventures

19. Play magician with disappearing candies

What makes these candies dissolve the fastest—and why? Your students will get a taste of the scientific method as they experiment with different liquids and leftover Halloween candy.

(Difficulty: Medium)

Try it: Dissolving Peeps

a melted puddle of a halloween candy with wax spots on the surface- Halloween science experiments — Candy Experiments

20. Wanna know what’s really in candy?

Who knew candy had more than just sugar in it? This experiment using Starbursts and heat is eye-opening.

(Difficulty: Medium)

Try it: Candy Oil Test

Haunted house made of paper and circuits for an experiment — Science Sparks

22. Build a haunted house

Using recycled materials and a simple circuit, build a haunted house that lights up from the inside.

(Difficulty: Medium)

Try it: Spooky Circuits

23. Make a vanishing ghost

Gather packing peanuts and use a permanent marker to draw ghost faces on them. Grab a bowl of water and watch the ghost disappear right before your eyes!

(Difficulty: Easy)

Try it: Amazing Vanishing Ghosts

Skeleton made of q-tips -Halloween science experiments — Thriving Home

24. Craft a skeleton

Using Q-tips, scissors, and glue, craft a model of a skeleton. Kids can position their skeletons in fun poses!

(Difficulty: Medium)

Try it: Q-Tip Skeleton Halloween Craft

Ghost made from a deflated balloon — Our Family Code

25. Create a ghost sound

On a white balloon, draw a ghost face with a permanent marker. Insert a small metal hex nut before blowing up the balloon and tying it off. When the balloon is swirled around, the hex nut will spin around on the inside, creating a spooky sound.

(Difficulty: Easy)

Try it: Spooky Ghost Sounds STEM Activity

Build an Edible Haunted House- Halloween science experiments — I Heart Naptime

26. Build an edible haunted house

Who says a haunted house can’t be tasty? Using candy, graham crackers, and frosting, build a haunted house that’s actually delicious!

(Difficulty: Easy)

Try it: Haunted Halloween Gingerbread House

Melting Skittles shaped like a pumpkin — Mombrite

27. Observe a melting pumpkin

Using orange Skittles, create an outline of a pumpkin in a plate. Slowly pour warm water on top and observe the colors melting into the liquid.

(Difficulty: Easy)

Try it: Pumpkin Skittles Experiment

Ghosts made out of tissue paper — We Are Teachers; Mombrite; The Homeschool Scientist

28. Use static electricity to fly ghosts

Cut out tissue paper ghosts and draw faces on them. Rub a balloon on your hair to create static electricity, then float it on top of the ghosts to make them fly!

(Difficulty: Easy)

Try it: Static Electricity Ghosts

Pumpkin made of orange pool noodle — STEAM Powered Family

29. Light up a pool noodle pumpkin

Carefully cut out a face design in an orange pool noodle. Then, create a play dough circuit that will light up the pumpkin from the inside.

(Difficulty: Advanced)

Try it: Halloween Pumpkin Squishy Circuits

Toy spider going up Lego bricks — Naomi Meredith—The Elementary STEM Coach

30. Make the spider go up the web

Attach a spider ring to a pencil using yarn. Then, build with LEGO bricks a device that can hold the pencil and have the spider move up the web by rolling the pencil.

(Difficulty: Medium)

Try it: Spider Pulley STEM Activity