57+ Halloween Science Experiments | The Ultimate List

Did you know there is a ton to be learned just from a simple pumpkin? Using this guide (and the free printable) you and your kids can observe and investigate pumpkin seeds, lines, weight, height, and more! It's fun and simple for all ages. Observation is a key facet of science, and this activity is all about that.

When you're done observing your pumpkins, move onto other harvest time produce such as apples, squash, and corn! The possibilities are endless!

What’s more fun at Halloween than explosions and projectiles? Why not make a soda bottle rocket this Halloween as part of your STEM fun?

Our family made a soda bottle rocket that is able to shoot an empty soda bottle more than 75 feet into the air – again and again and again! It was such a fun way to enjoy STEM education in our homeschool.

Learn how to make your own soda bottle rocket. This activity is fun for all ages but is geared towards older kids and teens (or younger kids with adult assistance). Or for a more young-child-friendly idea, enjoy a simple diet soda geyser.

To up the spooky factor, just decorate your flying rocket like a bat or a witch before blast off!

This experiment demonstrates principles of physical science and provides insight into gas pressure, nucleation, and the rapid release of carbon dioxide when Mentos candies disrupt the carbonated liquid's physical properties, creating an explosive, observable reaction that can be measured and analyzed.

This activity is not Halloween-specific but it’s still a fun way to bring some science into your Halloween festivities – especially if you throw in a little Halloween-themed coloring or flavors. Orange and black would make some cool-looking candy crystals!

Rock candy is a scientific activity that takes only an hour or two to put together but then keeps kids engaged and learning for more than a week thereafter. Because of the time this activity takes to grow, make sure you start this project well in advance of the day you want to eat.

The rock candy experiment illustrates the scientific principle of crystallization, providing a tangible way to observe how molecules form ordered, solid structures, and also demonstrates the concept of supersaturation in solutions, where more solute (sugar) is dissolved in a solvent (water) than it would normally be able to retain at room temperature, leading to crystal growth as the solution cools and the solute precipitates out.

Are you hosting or attending a Halloween party this year? Consider having your kids make and bring some rock candy to share! Learn how to enjoy your own rock candy experiment.

My friend Karyn over at teachbesideme.com has some super fun STEM projects with a Halloween theme – including these Halloween circuits.

What says Halloween better than oopey, goopey, Glow In The Dark Slime?

Seriously. This stuff is GROSS! (The good kind of gross, of course!)

Nadia from Fun With Mama has some instructions for a great Monster Slime recipe.

In the daylight, this Halloween slime is a nice green color. Fun and pleasant. But bring it into a dark room and it starts to GLOW. It’s very cool. And the longer this stuff is exposed to sunlight, the brighter it glows!

The trick to making Glow In The Dark Slime is one secret ingredient – glow in the dark powder (Who knew they powdered that stuff?) But if you want to skip the ‘glowing’ part, feel free to leave the glowing ingredient out.

Get the instructions for this fun Glow In The Dark Slime here

Alternatively, if you aren’t dead-set on glow in the dark slime and just want to explore a bunch of different slime recipes, read this post on using slime as a science fair project.

Creating glow-in-the-dark slime offers a delightful and tactile way to explore the science of luminescence and non-Newtonian fluids with our students. This engaging experiment allows us to spark discussions about how certain chemicals absorb and re-emit light, and why the slime behaves as both a solid and a liquid, providing a fun, hands-on approach to understanding these fascinating scientific phenomena together!

Have you ever put marshmallows in the microwave? Microwaved marshmallows are a fascinating (and super fun!) concept and this science experiment takes that messy adventure and adds a little bit of education.

This experiment is similar to the exploding Ivory soap experiment that we've included in our latest STEM Made Simple book. Now go make your own Halloween geyser using ghosty marshmallow peeps!

For a lot of kids, making homemade volcanoes is a beloved memory. But have you ever made an oozing pumpkin? As far as my kids are concerned, anything to do with slime or mess is a win in their book.

Kimberly of TeamCartwright.com has some detailed instructions on her site, along with some great scientific observations for a complete educational activity. These are very similar to the soda geysers mentioned above, but with a fun Halloween twist.

There are even scientific diagrams and multiple options for recipes, depending on what you are looking for. (I especially love that she explains the science behind it all) It’s quite detailed!

Thanks to all the different options and observations, this activity is great for kids of all ages!

Instead of experimenting with the explosive properties of baking soda and vinegar, let's have some fun with soap and bubbles! Find out how with this bubbling pumpkin experiment.

Similar to the Oozing Pumpkin experiment, this witch’s brew is just as slimy and just as fun. Instead of watching your goop explode up and out of your pumpkin, you get to mix potion ingredients into your very own cauldron, just like a real, creepy witch.

At the end of the experiment, dive into sensory play with the slimy goop you just created. It’s like Halloween slime only better!

Cindy from Living For The Sunshine makes this activity seem effortless with her detailed instructions and suggested accompanying activities. She gears her experiments towards preschoolers but even my upper elementary aged kids love this.

Have you ever experimented with melted crayons? This project doubles as both a STEAM activity and a fun art project. Plus, it's a great way to use up some of those old, broken crayons!

Melting crayons offers an exploration into the world of physical changes, allowing us to observe and discuss the concepts of melting points, heat transfer, and the transition of materials from a solid to a liquid state. It’s a colorful and creative way for us to visually understand and appreciate the effects of heat on different substances, while also exploring the artistic potential of science together!

If nasty, goopy pumpkin guts don't gross you out, you'll probably get a kick out of this pumpkin guts slime activity. Make your own slime using the insides of your pumpkins and jack-o-lanterns! Fun, child-safe, and quite memorable.

The Joys of Boys has a great Halloween science experiment – Grow A Monster!

This experiment takes the chemical reaction of vinegar and baking soda and uses the gases created to blow up a monster balloon. This is a super fun DIY STEAM activity that kids can do all by themselves!

During my search for experts to contribute to this roundup, I ran into Marie.

Marie from Fun With Mama has a GREAT Halloween-themed science experiment on her blog – A Mad Scientist Lab! (She’s got a bunch of other Halloween activities on her blog too, but for now, we’ll focus on the Mad Scientist Lab.)

Similar to the oozing pumpkin experiment listed above, this Mad Scientist Love is a super fun way to dig into some chemicals and make some fizzing, erupting explosions.

I love how these beakers give this activity a nice finished touch.

This is one of those fun Halloween science experiments that gives kids some lasting Halloween memories.

As a kid, I am certain I would have loved doing this. And I was never into science experiments as a kid.

My own kids will probably do this experiment at least a half a dozen times before October is over.

While this activity is specifically geared towards our youngest kiddos, there is plenty of room for discussion. Learn bout gravity, absorption, hydrophilic materials, and more! Plus, your kids will be able to end the project with a beautiful artistic creation.

We are a big fan of hands-on experiments at my house. And I’ve been itching to try this shaving cream rain experiment for a while now.

Doesn’t this look so fun?

It almost looks good enough to eat! (don’t!)

Although on that note – I wonder how this would work with whipped cream instead of shaving cream? Looks like we’ve got another fun Halloween science experiment on our hands…

This experiment shows kids an up-close-and-personal version of a rain cloud (and the associate rainstorm.) Even older kids can have fun making their own storm-in-a-jar.

Emily writes these instructions in the summertime – but with some orange coloring, you can easily make this a Halloween-themed activity. (It rains on Halloween, right?)

If you ask me, my favorite science experiments are the ones that are edible.

What can I say? I just LOVE FOOD!

This mad scientist punch is a fun Halloween-themed science experiment that you get to eat (drink) after. I call that a win!

When you combine ginger ale with sherbet, you create a fizzing chemical reaction. This chemical reaction looks like a mad scientist explosion. It’s a lot of fun!

Now Ashley doesn’t talk about this STEM activity from a Halloween perspective, but it would not be hard to tie this into some Halloween festivities.

Just imagine you are receiving a letter from a ghost? Or you’re writing a letter to a ghost? Or maybe you’re drawing a secret map that leads to a buried Halloween treasure!

Older kiddos could write their secret letters in a different language (or secret code) thus making the message even more secret.

Or make a secret invitation to a Halloween party.

The possibilities are endless!

My kids are always engaging in some type of imaginative play. And these invisible ink letters play into that perfectly. It’s so fun to see a secret message appear like magic!

And Ashley goes into detail about the science behind this STEM activity (oxidation) so even though it’s fun, it’s completely educational!

These creepy glowing Halloween lanterns make such a fun and decorative Halloween activity.

These are made by taking a glow stick, cutting it open, and dumping the contents into a glass jar.

Due to the nature of this activity, kids should definitely be supervised by adults.

Have you ever seen a floating pumpkin? In this experiment, your kids will be able to make their pumpkins levitate, or float! This is a fascinating project that will leave all your kids saying, "Wow!".

You're probably familiar with the concept of toothpick bridges. In fact, we did a toothpick bridges STEM challenge here. Add a Halloween twist to an otherwise year-round activity by using Halloween-themed candy pieces instead! Build bridges or simple structures and shapes, depending on your child's age. It's a great way to teach engineering concepts!

This fizzing bats activity from Monique at livinglifeandlearning.com is another child-friendly favorite.

The concept is simple. You make bats using a combination of baking soda, coloring, and cookie cutters. Get your hands messy while making your bats. When you’re done playing with step one and are ready to move into step two, get out your vinegar and dump it on your bats. Watch them fizz and bubble and enjoy the giggles of young children!

Making borax crystals is a very popular experiment for elementary ages. This simple experiment can get even more exciting when you manipulate the shape and the color of your crystals.

Making borax crystals with our students gives us a window into the world of crystallography, allowing us to explore and discuss the fascinating process of how crystals form through the slow cooling of a supersaturated solution, and how molecules arrange themselves to create the sparkling structures we see.

Why not try a fall-themed crystal shape that's perfect for the season?

Salt painting is another fun yet simple activity for younger kids. In this project, your kids will make their own fall or Halloween-themed shapes and then paint them using glue, salt, and paint. Lots of fun and perfect for this time of year.

Have you ever wondered if a pumpkin floats? At first glance, pumpkins are BIG and HEAVY! Of course they don’t float! But upon further investigation, you might discover your first impulse answer was wrong.

Explore this Halloween science experiment with your kiddos and let them find out for themselves if pumpkins will sink or float – and then discuss why.

Ticia from adventuresinmommydom.org has a great walk-through of this simple Halloween experiment, complete with instructions for turning this into an even more detailed adventure.

Have you ever seen an egg glow in the dark? This experiment creates eggs that spookily glow and give off the perfect Halloween aura. Learn what happens when you combine calcium carbonate (the shell) with vinegar. This is a fun and simple activity your kids will talk about for many years to come.

Here is another version of the baking soda and vinegar balloons experiment. This one uses balloons that are decorated to look like Jack-O-Lanterns or pumpkins. Fun, quick, and easy!

For some reason, homemade root beer is traditionally associated with Halloween. This year as you're making your seasonal treat, include some educational aspects regarding the dry ice.

Dry ice is a fascinating material and there is so much to be learned when (safely) observing this object,

Vikki from A Plus Teaching Resources is at it again with this great Halloween STEM activity – Marshmallow Eyeballs.

There is so much science involved in cooking and baking. (and a whole lot of art too!) I know when I’m working in the kitchen, my food turns out a whole lot better if I apply my science knowledge to my cooking, instead of just blindly following a recipe.

I want my kids to grow up learning that same crucial kitchen tip.

So we spend a lot of our STEAM time in the kitchen.

These easy Halloween-Themed Marshmallow Eyeballs are the perfect kitchen activity for kids. I mean, how gross are these? The ideal Halloween treat! And a step up from the traditional candy corn Halloween candy.

This painted rocks project is such a fun Halloween activity with a twist of STEAM! These rocks are not painted with a normal paintbrush dipped in paint. Nope!

These rocks are painted using PHYSICS!

How cool is this?

This does take the purchase of a special art spinning machine.

We've done this experiment using plastic dragons in the past but you can certainly enjoy a Halloween twist by making plastic ghosts! This experiment is a good way to learn about static electricity and it only requires a couple of materials.

Charlotte Mason homeschoolers will love this next one. Cindy from ourjourneywestward.com has an entire article devoted solely to living math and science using pumpkins. Did you know there is a lot to be learned and explored with one simple pumpkin?

Cindy walks you and your kids through exactly how to turn your pumpkin into an in-depth educational adventure. Find the circumference and the diameter of your pumpkin. Count the vertical lines on your pumpkin and then calculate different things such as percentages and fractions. Measure the volume of your pumpkin using water displacement or enjoy pumpkin races!

Details surrounding all these experiments and more can be found at ourjourneywestward.com

You've floated pumpkins, but have you ever floated Halloween candy?

This experiment is super simple and if you go Trick or Treating, you'll be using items you already have on hand - Halloween candy!

Conduct an experiment with your kids. Make a hypothesis as to which candies will sink and which will float. Then perform your experiment and record your results!

You might know what Halloween candies sink or float, but do you know which candies dissolve? Experiment with even more states of matter with this simple science activity.

Have you ever asked yourself what happens to a rotting pumpkin> Over at kitactivitiesblog.com, they're performing an experiment to determine just that!

This is the perfect experiment for anybody who carves Jack-O-Lanterns before Halloween but then doesn't know what to do with them afterwards.

This project definitely requires some adult supervision since it uses fire. Star by decorating some green tea bags to look like ghosts. Then light them on fire and see how long it takes them to float!

When you're done, you and your kids will have plenty of opportunities for discussion.

This is a super simple yet super fun science experiment that even the youngest of learners can enjoy. All you need is skittles, water, and a plate.

Have your kids make a pumpkin out of skittles. Then add a little bit of water and wait for the colors to bleed. Fun and easy!

Yet another exploding pumpkin experiment. This project never gets old!

Have you seen my exploding sidewalk chalk science experiment? This exploding Jack-O-Lantern activity takes the same concepts and adds a Halloweeny theme. Perfect for kids of all ages!

If your little ones benefit from sensory bins, they will love this Halloween-themed one from theinspirationedit.com. This activity is fun and safe for preschoolers, kindergarteners, and kiddos with special needs. Plus, it's just plain fun!

Study osmosis with this fun gummy bear osmosis science experiment! This activity is perfect for those gummy bears that are leftover from Trick or Treating. Learn what happens to gummy bears when they're soaked in various solutions. Then apply this lesson to other aspects of life.

If your kids like playing with their food, they are going to love this Frankenworms science experiment. Perfect for Halloween, this STEM activity involves ooey gooey gummy worms. Watch how your worms react to different elements!

This science experiment is so simple it's almost like magic! Using magnets, your kiddos will get to make their little ghosts float. Explore magnetic fields and learn why some magnets attract and other magnets repel.

This science activity is complex enough to replace an entire day's (or week's) worth of science lessons, or simple enough to enjoy after school or on the weekend. And it is fun for all ages (including adult!)

This STEAM activity also doubles as a sensory activity. Let your kids build their very own pumpkins out of everyday household materials. When you're done getting messy, make the mess even bigger and watch your pumpkins melt! This activity is incredibly engaging and perfect for kids.

Do you know how to make a spider web? With this activity, you'll get to learn how!

Using physics, kids will get to build their very own spider webs out of yarn, uncooked spaghetti, and store-bought spider web decorations.

They will have to determine which material makes the best/strongest web and then answer the question as to why. It's a ton of fun and highly educational!

These candy corn catapults are the perfect example of a Halloween science experiment. Apply various aspects of STEM and build a catapult (using everyday household materials). then see how far you can launch your candy corn pieces.

Whether you enjoy eating candy corn or not, you will certainly enjoy watching them fly across the room!

Have you ever made a lava lamp? I haven't but according to this post, it's surprisingly easy! Make your very own Halloween lava lamp today!

One of the best things about STEAM is a lot of the experiments work almost like magic! Yes, it's science, but it's still incredibly cool. Combine the forces of science and magic and make your very own possessed bones!

Here is another example of the floating ghosts experiment. Using static electricity, you can make your homemade ghosts float!

Turn science into a friendly competition with Halloween balloon races.

During the spring, we talk about the life cycle of butterflies and other bugs, but what about in the fall? What life cycle do we have to think about then?

Why, pumpkins of course!

Kallysclarroomonline.com takes an in-depth look at the life cycle of a pumpkin and how your kids can learn about pumpkins, produce, and life itself during the Halloween and harvest seasons.

This activity is a little bit creepy but a lot of fun. Your kids will get to make a goopey, slimy, blood cell model. And this scientific activity doubles as a sensory activity for younger or special needs kiddos too.

You'll need a few specialty ingredients but you'll find all the details over at adabofgluewildo.com. This activity is appropriate for grades PreK-12, depending on how deeply you dive into the science.

What happens when you put a marshmallow in the microwave? The answer might surprise you. Experiment with marshmallows in this Halloween science experiment.

Using old film canisters (or other small plastic containers) and Alka Seltzer tablets, your kids can make their very own ghost rockets!

These rockets may be small but that doesn't mean they're any less fun. Do you know how high your ghosts will fly? Perform the experiment to find out!

Use your leftover Halloween candy to enjoy this edible rock cycle experiment. Teach kids all about rocks and their life cycles (sedimentary, metamorphic, igneous, etc), all with simple pieces of candy. It's fun and educational too! (Not to mention delicious.)

Here is another science experiment that doubles as a sensory activity. Have some fun with moon dough and then when you're done, watch your homemade ghosts fizz away!

Turn your Trick or Treating adventures into a full-in science lesson by charting and graphing your Halloween goodies! Have your kids sort, count, track, and compare everything they got on Halloween. This is a fun and simple way to enjoy some Halloween science without making a mess or excluding older or younger siblings!

Learn about non-Newtonian fluids with this DIY Halloween monster slime recipe. You could even save the slime for another day and play with it again and again!