30 Halloween Science Experiments for the Elementary Classroom

These 30 Halloween science experiments cover the full range of elementary science. You will find physical science experiments, earth science activities, life science explorations, and a STEM category — all organized so you can quickly match an activity to your curriculum.

From vanishing ghosts and density experiments to chemical reactions and pumpkin explorations, there is something here for every grade level and every October lesson plan.

30 Halloween Science Experiments for Elementary Classrooms

Physical Science Halloween Science Activities

Below are 18 ideas for Halloween science experiments focused on properties of matter, irreversible changes, density, and more!

1. Vanishing Ghosts

The Vanishing Ghosts experiment is easy to set up, needs few materials, and is a favorite Halloween science experiment. It’s perfect for younger students, but older students will enjoy it, too!

I like to set this one up before students arrive and let them walk in to find the ghost already mid-vanish. The reaction happens relatively slowly, so it works well as a station students check on throughout the day rather than a sit-and-watch experiment. By the time they come back from lunch, the ghost has completely disappeared, and the conversation about what happened writes itself.

2. Flying Tea Bag Ghosts

This activity teaches your students about convection and air pressure. What’s Halloween without some ghosts flying around? This activity goes along with our Second Grade Properties of Matter Science Stations.

I do this one as a teacher demonstration rather than a student activity because of the fire. Students gather around and record their predictions on a recording sheet before I light the bag — most predict the ash will fall, so watching it rise is a genuine surprise. After the demonstration, we go back to their prediction sheets and they write what actually happened and why. The convection concept sticks because they were wrong in an interesting way.

Safety tip: Fire is involved, so do take necessary precautions.

3. Apple Volcanoes

Chemical reactions at their best! What can be more fun, or messier, than a little vinegar, baking soda, and food coloring? Make your own apple volcanoes.  Links are also available for larger volcanoes, like pumpkins.  

If your students have done the classic baking soda and vinegar reaction before, this is a good opportunity to ask them to predict what will happen before you add the food coloring — most already know the reaction is coming, but the containment inside the apple changes how it looks and flows. Students who are surprised by how quickly the reaction fills the cavity tend to ask the best follow-up questions.

4. Spooky Expanding Ghost

More baking soda and vinegar fun. This spooky expanding ghost experiment will amaze your students. Note: Pressure can build to a point where the ghosts might vanish with a loud pop!

5. Slime Monsters

Here’s an experiment so fascinating it’s scary! Students make their own magnetic Halloween slime monsters. If you’re in the middle of a third-grade magnetic forces unit, this is a wonderful addition to those science experiments!

6. Creepy Density

This fun experiment explores density and is perfect for second graders exploring the properties of matter.  Make this as creepy as you want with red food coloring and creepy toy bugs.

This one pairs directly with the Properties of Matter science stations if you are doing that unit in the fall. Before students set up their density columns, I ask them to predict the order the liquids will settle and sketch it on a recording sheet. Students with the most confident wrong predictions usually end up most interested in figuring out why the actual result looked different. The red food coloring makes the layers easy to photograph for quick documentation.

7. Dancing Ghosts, Bats, and Witches

Do not miss using this fun lesson on static electricity!  This activity will have your students howling with laughter. Tip: This works with any Halloween-themed silhouette you can imagine!  And it pairs well with our Static Electricity Science Stations!

One thing I have noticed: this experiment is very sensitive to the humidity in the classroom. On dry days it works immediately. On humid days, students may need to charge the balloon longer or try a different material. Rather than treat this as a problem, I use it as the actual lesson — we talk about why it might not be working the same way in every group, which leads to a real conversation about variables. This pairs directly with the Static Electricity Science Stations if you are covering that standard in October.

8. Alien Monster Eggs

Want to gross out the whole school? Make your class the Halloween school party hit and make some Alien Monster Eggs.  Your students will learn about acids and molecular structure while making the grossest display. Winner!

9. Dancing Frankenworms

Here is another scary fun experiment. Grab some gummy worms and make them come alive! See if your students can figure out what makes the worms dance

10. Spooky Dry Ice Experiments

What is spookier than a bubbling cauldron, or eerie fog creeping everywhere? Remember, handle dry ice with care. Take appropriate safety measures!

Here is an example of the dry ice experiment in our classroom with a fun Halloween treat!

I told the students what we were going to do, and we made some predictions about what would happen.  We made a list as a class, and each student went back to their desk to fill in the top part of their recording sheet.

During the experiment, we gathered around the table and talked about what happens with regular ice versus dry ice.  The kids loved it!  

To follow through, students wrote about the experiment on their science experiment recording sheet. Students LOVED doing this fun Halloween science experiment, and it makes a fantastic addition to a Halloween Party!

11. Flying Ghost Rockets

Have you ever wanted to watch a ghost fly? Your students launch these ghosts and learn about pressure and chemical reactions at the same time! Note: You can use any plastic container for this spooky Halloween science experiment.

12. Candy Potions

Combine the magic of Halloween and Science with your own potions! Get your students to brew their potions and learn about chemical reactions!

13. Pumpkin Oobleck

Who doesn’t love playing with Oobleck? The non-Newtonian liquid is fun for younger students and older students (or teachers?) alike. Here’s how to make a pumpkin version.

Oobleck is one of those activities where the mess is part of the point, so I put down a large plastic tablecloth and have students work in pairs. The question I always ask before we start is, “Is this a solid or a liquid?” Students record their answer, then spend time pressing, punching, and scooping the oobleck before recording again. Most change their answer at least once. The pumpkin version adds orange food coloring and a little cinnamon, making the whole room smell like fall while students try to figure out the science.

14. Bubbling Boo Bombs

Want to see bubbling ghosts and exploding pumpkins? Of course! Who wouldn’t? Here is another fun experiment on chemical reactions that will be a hit with your students.

15. Exploding Pumpkin

Ever think to yourself, there must be an easier way to carve a pumpkin? Try this experiment with your students and explode their minds! Safety tip: Chemicals used in this are highly explosive; use care and follow Steve Spangler’s instructions.

16. Glow-In-The-Dark Slime

What would Halloween be without something that glows in the dark? Could it be slime? Yes, please! This is a must-do experiment for your students this Halloween.

17. Exploding Ghosts

You’ll need a microwave for this one. Students will love watching these gooey ghost geysers explode. Keep a close eye on the experiment; it happens quickly!

18. Haunted Hands

How does salt melt ice? Explore this spooky experiment with your students and watch the hands vanish! Here are tips to make this experiment as spooky as possible.

Earth Science Halloween Science Experiments

Here is an idea for Earth science and erosion.  This goes well with our second-grade science units.

19. Disappearing Candy Pumpkins

Do your students have too much Halloween candy? (Do their parents say they have too much?) Or, do you? Here’s a fun experiment to help you solve that problem and learn about erosion in the process. Maybe set aside some of the candy for a snack while you observe.

Life Science Halloween Science Activities

Below are 8 ideas for Halloween science experiments and activities focused on plant growth, blood, skeletons, and more!

20. Growing Pumpkins Inside Pumpkins

This is a fun one that you need to start before Halloween. Here are detailed instructions on growing your own pumpkins with the seeds from the original pumpkin.

Give this at least a week before you start to see any sprouts.  Or if you’re doing our Pumpkin Exploration activity, save some of the seeds, dry them out, and use them during the spring life science units.

21. Monster Plants

Another fun experiment in how plants grow with a twist! Let your students decorate their cups to create their very own pet monsters. Start the experiment long before Halloween to give the plants enough time to grow and be ready.

22. Bloody Mess

Gather your little vampires around for this one. Here is an experiment that students can really sink their teeth… I mean, hands,  into! It’s a way to teach about the many different cells that compose our blood. It complements our Fourth Grade Structures and Functions of Organisms Science Stations.

I have used this one to introduce the structures and functions of organisms unit before getting into the science stations. Students are always fascinated by how many components blood actually has — most think of it as one uniform red liquid. Using a zip-lock bag, red-dyed water, white candies for white blood cells, red candies for red blood cells, and yellow water as plasma gives students something to point to when they explain the parts later. This complements the Fourth Grade Structures and Functions unit, especially before the Diagram Heart station.

23. Creepy Gelatin Heart

If you’ve ever wondered how to teach your students about the human heart and make it yummy, wonder no more!  Here is a video just for you.  Bonus: You can make a brain instead!  This also goes along with our Fourth Grade Structures and Functions Unit, especially the Diagram Heart Station.

24. Skeleton Puzzle

Teaching your students about the human skeleton? Kids love learning about their own bodies. They can bone up on their knowledge with life-size puzzles. Choose and print from the numerous free options on eskeletons.org.

25. Vampire Blood

Want to wow your students more than scare them? This fun experiment is just what you need: an activity to learn about chlorophyll and light.  This pairs nicely with our third-grade science stations on leaf traits.

26. Pumpkin Slime (With Real Pumpkin)

Ooey-Gooey gross! Let’s face it, kids love slime. Students can make pumpkin slime with real pumpkins. Students learn about the different parts of the pumpkin while creating a grotesque explosion of pumpkin guts!

27. Rotting Pumpkin Jack

This one starts before Halloween and extends afterward. It’s a way for your students to explore the full life cycle of a pumpkin and observe how it decomposes. 

If you choose to do this experiment, check out this blog post for some fun books you can use to enhance students’ understanding of the pumpkin life cycle.

This one requires patience, which makes it worth doing because not many elementary science activities do. I set the jack-o-lantern on a table at the back of the room on the day we carve it and have students sketch it in their science notebooks. We go back weekly — sometimes more often if the decomposition is moving quickly — and students draw what they observe each time. By the end of November, the change is dramatic enough that students who forgot what the original pumpkin looked like are shocked when they compare their sketches. It is also a natural conversation starter about what decomposers need and where they come from.

STEM Halloween Science Activities

Here are 3 ideas for Halloween STEM science activities that will engage your elementary students!

28. Candy Pumpkin Structures

It’s scary how creative your students can be with this simple STEM project. Let them amaze you with this yummy activity.  Another simple set-up activity that will bring countless minutes, if not hours, of creative fun. You can also do this experiment with candy corn!

If some of the candy pumpkins disappear, just blame the ghosts!

29. Geoboard Pumpkin

Geoboards are a fun math learning experiment for any age. Younger students can develop their fine motor skills. Older students can learn basic math/geometry skills while creating their masterpiece designs.

30. Pumpkin Catapults

Doesn’t the title say it all? Pumpkin. Catapults. Let them figure out the best design for a catapult that shoots the farthest. Discuss how catapults work, and watch the creativity explode!

I give students a design constraint before they start: the catapult has to launch the pumpkin at least one foot using only the materials in the bag. Groups who finish the first design quickly get a second challenge — launch it farther, or launch it more accurately. The conversation about what makes one design work better than another is where the STEM learning actually happens, so I build in time at the end for groups to share what they changed and why. Students who struggled with the first design usually have the most to say.

As a teacher, love being able to turn a holiday or a treat into a teachable moment. When we don’t have much time for science, these Halloween science experiments, activities, and ideas are a perfect way to introduce the scientific method through a high-interest activity.

From this list of 30 spooky Halloween experiments, which one was your favorite?

Use the Scientific Method to Teach These Halloween Science Experiments

While we want students to have fun with these Halloween science activities, that doesn’t mean you can’t work on academics, too. These experiments are an opportunity to practice the Scientific Method and Science Experiments.  Show students how scientists work through a process that asks a question and searches for an answer. 

The Scientific Method Posters and Science Experiment Recording Sheets help students connect these science activities to science learning. Here are a few photos from the Scientific Method Resource.

Included in the Scientific Method Teaching Resource are:

• posters in color and black and white for every step of the scientific process
• vocabulary cards in color and black and white that you can hang on your wall
• experiment recording sheets and a flipbook that students can use for more in-depth research projects

The Scientific Method Posters and Science Experiment Recording Sheets can be used for any science experiment.  They are a year-round resource for all your science exploration.