Every day is a new opportunity for toddlers to ask “Why?” over and over. Tap into that curiosity with these fun and engaging preschool science experiments and activities. They are easy to set up since most require little more than items you likely already have at home. These experiments incorporate many young children’s favorite activities like playing with bubbles or water, making arts and crafts, and, of course, making a mess!

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1. Try this “The Floor Is Lava” STEM challenge

Toy bears stacked on plastic cups, wood craft sticks, and index cards

While you might not want pre-K kids climbing all over the classroom furniture to play “The Floor Is Lava,” they can do the same thing with their toys in this cute STEM challenge!

Learn more: Forward With Fun

2. Surround kids with an oversized bubble

A little girl is standing in a kiddie pool. A hula hoop surrounds her and a giant bubble. (preschool science)

Kids (and let’s face it, adults too) will definitely get a kick out of this fun science experiment. While you’ll only need a hard-shell kiddie pool, some dish soap, and a Hula-Hoop to make this a reality, the payoff will be big. If you’re doing this inside, we recommend a step stool too so kids can avoid getting covered in bubble solution!

Learn more: Make and Takes

3. Watch rice dance in water

Glass of blue liquid with rice floating and moving in it (Preschool Science)

There are lots of cool baking-soda-and-vinegar experiments out there (ever made your own volcano?), but this one is always a favorite with little ones. The acid-base reaction causes the rice to dance and jump around in the water for an effect that is just so cool!

Learn more: Green Kid Crafts

4. Reveal colors with chemical reactions

Preschool student squeezing a bottle of vinegar into muffin tin cups filled with baking soda and food coloring

Preschool science experiments often include a combination of baking-soda-and-vinegar like this one. Fill muffin tins with a drop of food coloring, then top it with baking soda. Finally, let kids squirt in vinegar to reveal fabulous foamy hues!

Learn more: Busy Toddler

5. Build a catapult

popsicle sticks and elastics are stacked to create a catapult. A plastic spoon makes for the actual catapult piece (preschool science)

Challenge students to build a catapult using just three items: Popsicle sticks, elastics, and a plastic spoon. You’ll definitely want to have an extra set of adult hands available as this can prove challenging for pre-K kids. Finally, bring plenty of marshmallows or pom-poms to launch!

Learn more: Education.com

6. Discover strength in shapes

Three pieces of paper folded into columns as circle, square, and triangle

Learn shapes while also practicing some basic science. Fold paper into various shapes to form columns and ask kids to predict which will be able to support the most books.

Learn more: All for the Boys

7. See what sinks and what floats

Preschool science student placing objects in bins of water to see if they sink or float

We love this experiment since kids always enjoy playing around in water. This preschool science activity helps them learn to construct a hypothesis, conduct a simple experiment, and then sort their findings by property.

Learn more: Fun With Mama

8. Grow grass in an eggshell

Two egg shells have faces drawn on them and grass growing out of top of them.

What’s more fun than a preschool science experiment that doubles as a craft? You’ll need eggs, soil, grass seeds, water, and a permanent marker to bring this project to life. Kids will especially love personalizing their eggshell. Finally, let kids check on their egg friends every day to see the progress their hair is making!

Learn more: Mother Natured

9. Learn what dissolves in water

Preschool science student mixing various solids into glasses of water

Engage in more water play by having kids predict which items will dissolve in water and which ones won’t. Have kids keep track of the results so they can see if they have anything in common.

Learn more: Hands On as We Grow

10. Build an aluminum foil boat

A tin foil boat holds a bunch of pennies and is seen floating in green water.

Teach kids about buoyancy and physics while having fun in the process. First, give your students some tinfoil and challenge them to build a sturdy boat. Then, challenge them to fill the boat with as many pennies as they can without it sinking.

Learn more: Little Bins for Little Hands

11. Watch hot water rise and cold water sink

Plastic bin of colored water, with red on top and blue on the bottom

This early exploration into the concept of density is always impressive to see in action. Have kids discover how hot water rises and cold water sinks. Explain that the same applies to air, and see if kids can think of a way to observe that in action too.

Learn more: Mombrite

12. Grow a paper towel rainbow

Paper towel strip draped between two glasses of water, with colorful marker rainbow ink moving from each side to meet in the middle (Preschool Science)

“Capillary action” might be a real mouthful for preschool science students, but they don’t need to remember the term to be impressed by this experiment! All you need are markers, a paper towel, and two glasses of water.

Learn more: Mombrite

13. Show why sunscreen is important

Plastic wrap, sunscreen, and an outline of a person on construction paper is shown (preschool science)

four construction paper people are shown. One is wearing a hat, one is wrapped in plastic wrap, one is plain, and one is wearing sunglasses.

This experiment would be best suited for summer, although it could still work other times of the year. First, have your students make four construction-paper people each with varying conditions. Have one wrapped in plastic wrap, another covered in sunscreen, put a hat on one and a set of sunglasses on another. Finally, have students hypothesize what will happen when they are left in the sun.

Learn more: 123Homeschool4me

14. Engage in some shadow science

A jar contains straws with black silhouettes of animals attached to them (preschool science)

Despite the cold temperatures, kids will still enjoy getting outside to experiment with shadows. These adorable animal puppets are so cute, and the kids will have a blast putting on a shadow puppet show.

Learn more: Little Bin for Little Hands

15. Mix up some “magic” milk

Preschool science student mixing a bowl of colorful milk swirls

A drop or two of dish soap will make food coloring dance and swirl across the surface of a shallow bowl of milk. Preschool science experiments often seem like magic, but this one is all about surface tension and chemical reactions.

Learn more: Laughing Kids Learn

16. See how easily germs spread

Lysol glitter germs science experiment

We love a preschool science experiment that reminds little ones of the importance of good handwashing. Help them see why it’s so important with this simple experiment that uses glitter to stand in for germs.

17. Experiment with wax paper

A child's hand is shown in front of a bright colored wax paper drawing.

You’ll need wax paper, glossy white paper, a spray bottle filled with food coloring, a plastic bin, and also an iron and ironing board to complete this experiment. Equally engaging from an art or science perspective, kids will have fun seeing the ways in which the wax paper creates a pattern when sprayed with color.

Learn more: Housing a Forest

18. Predict and observe what will melt in the sun

Muffin tin with different objects in each well (Preschool Science)

You’ll need a hot sunny day for this preschool science experiment. Help students choose a variety of items to place into a muffin tin and have them predict which ones will melt. Set the tin out in the sun for an hour or two, then bring it in and record your results.

Learn more: Frugal Fun 4 Boys and Girls

19. Build an apple toothpick tower

Preschool science student using toothpicks and apple pieces to build a tower

Put a healthy spin on a classic STEM challenge by substituting apple pieces for marshmallows. Kids will have a tasty snack when they’re done!

Learn more: Preschool Powol Packets

20. Make shaving cream rain clouds

Square glass vase filled with water with shaving cream floating on top. Food coloring is dripping down through the cream into the water.

This is a classic science activity every kid should try at least once. It helps them understand how clouds become so saturated with water that they must release it in the form of rain.

Learn more: One Little Project

21. Drop balls to introduce friction

Toddler holding a blue rubber ball

Gravity can be a complicated subject, but all pre-K kids need to understand the basics. Drop balls of all sizes to discover that they all fall in the exact same way.

Learn more: Inspiration Laboratories

22. Head to the playground to explore gravity and friction

Preschool science student sending a rock down a playground slide

What goes up must come down! A playground slide is the perfect place to help kids understand gravity. This is a good chance to learn about friction too.

Learn more: Buggy and Buddy

23. Test objects with magnets

Preschool science student using a bar magnet to test other objects

Magnets are undeniably a source of fascination for kids. At this stage, you can worry less about explaining how magnets work and instead just let kids explore which items are attracted to magnets and which aren’t. Have them sort the items into categories, then see if the items have anything in common.

Learn more: PreKinders

24. See sound waves in action

Glass bowl covered in plastic wrap with confetti on top, and a tuning fork touching the plastic

This series of simple experiments lets kids see sound waves at work. Start by making waves with a Slinky, then move on to tuning forks and bouncing confetti.

Learn more: Hands On Teaching Ideas

25. Make an orange volcano

An orange is shown in a bowl with a pitcher of red liquid pouring into the cut off top of it.

Since making erupting volcanoes is a staple of any childhood, we would be remiss not to include this fun and simple one made from an orange. In addition to the orange, you’ll also need baking soda and vinegar.

Learn more: The Art Kit Blog

26. Grow delicious rock candy crystals

Rainbow colored jars with rock candy sticks in each

While crystal experiments are a hit with kids of any age, this one is perfect for the pre-K crowd. It requires a little patience, but kids get to eat the yummy results!

Learn more: Growing a Jeweled Rose

27. Move pom-poms with air pressure

Young student using a straw in a plastic bag with sponges to move a green pompom across a wood table

Understanding the idea that air can have enough force to move objects can be a little challenging, but this simple experiment brings that concept to life. We love that this experiment is affordable since most people (especially teachers) have these materials at home.

Learn more: Kids Activities Blog

28. Blow bubble towers

Preschool science student blowing a tower of soap bubbles

There are lots of fun science activities you can do with bubbles to explore concepts like surface tension. Or you can just have a blast seeing who can make the tallest tower with bubbles and straws!

Learn more: Happy Hooligans

29. Make a balance scale

A little girl is seen filling a cup in a homemade scale.

This simple balance scale is so easy to make yet provides endless opportunities for weighing all kinds of objects. Have kids assemble a scale from a plastic hanger, a few paper cups, and some string, then let them hypothesize which items will be heavier and which will be lighter.

Learn more: Go Science Kids

30. Make pretend snow

A hand is shown holding fake snow from a pile.

Since there are multiple ways to make fake snow, choose the one that best fits what’s in your cabinet. This is an especially fun experiment to do with young kids during the winter months.

Learn more: Elf on the Shelf

Need more ways to help little ones learn? Stock your classroom with these 30 Best Educational Toys and Games for Preschool.

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Tap into the curiosity of young minds with these preschool science experiments and activities. Make rice dance, build apple towers, and more!