Science experiments for toddlers don’t need expensive kits — they need simple materials, a little mess, and a parent willing to let curiosity drive. This guide covers 25 of our favorite easy science experiments for toddlers from age 2 and up, with setup tips and links to full tutorials for each one.
If you are looking for easy science experiments for toddlers to learn and enjoy, these are our top favorites so far!
All of these science experiments for toddlers are age-appropriate and fun and have been tested and approved by my toddler 2-year-old toddler as well as my sensory students.
Science with toddlers does not need to look like a lab coat, a worksheet, or a perfect little Pinterest tray that nobody is allowed to touch.
Most of the time, toddler science looks like pouring water back and forth until their socks are wet. It looks like poking oobleck with one finger, then a whole hand, then maybe a toy dinosaur. It looks like asking, “What happens if we add more vinegar?” and then watching their face when the bubbles appear.
That is the kind of science I love most. As a play-based educator and the creator of Wonder Labs, my local hands-on science class for young children, I have learned that the best toddler science experiments are simple, visual, sensory, and open-ended. Toddlers do not need long explanations. They need materials they can touch, pour, squeeze, mix, observe, and explore.
What is science for toddlers?
Toddler science is not about memorizing facts. It is about noticing.
When a toddler watches food coloring spread through water, that is observation. When they guess whether a rock will sink or float, that is prediction. When they pour vinegar onto baking soda again and again, that is cause and effect. When they touch oobleck and realize it can feel hard and soft, that is sensory play doing real science work.
At this age, science should feel like play, because play is how toddlers test the world.
The Best science experiments for toddlers
#1 Volcanic Eruption
Also called Witch’s Brew, this science experiment for toddlers is number 1 on our list because it is so easy to make, it is so much fun to do, and the kids can do it themselves.
To do this experiment, you only need baking soda and vinegar. Mixing the two creates a magic explosion that is safe for little ones and a lot of fun.
Use food coloring to change the color of the bubbles. Add water to the vinegar to dilute and expand its use. The kids love to pour and see the bubbles repeatedly, so this will extend the activity for extra playtime.
Learn how to set up this witches brew experiment with step-by-step instructions
#2 Fizzy Cubes
To make fizzy cubes, freeze a mixture of baking soda and water. Activate with vinegar in the same way mentioned above.
To change the activity and work fine motor skills, this activity was set up using a dropper to suck the vinegar and squeeze it into the fizzy cube.
My toddler tried it several times but wanted a faster way to dissolve the cubes. He enjoyed grabbing each fizzy cube and dropping them into the vinegar cup.
#3 Oobleck
Making Oobleck is one of my favorite activities, but it can get messy! When you grab this substance, it is solid but melts and becomes liquid when you let go of the pressure.
To do this science experiment, all you need is two parts cornstarch and 1 part water.
Watch our quick video or get the step-by-step instructions and learn how to make Oobleck
#4 Sink or Float
Understanding weight is one of the first science experiments you can do at home. All you need is a bowl of water and a few water-safe objects.
Start by identifying what happens when each object touches the water. Repetition here is key!
Once the toddler grasps the new vocabulary words and correctly identifies what is happening, then try to ask before the item gets dropped to guess what he thinks is going to happen.
You can repeat this experiment during bath time, at the pool, or anywhere else you can access water.
Learn how to set up the sink of float experiment with step-by-step instructions
#5 Hot and Cold
Learn about temperature using sensory bottles. We filled one bottle of water with cold water, added a few ice cubes, and filled another one with hot water. We dyed the cold water blue and the hot water yellow to help associate the concepts.
We also paired this opposite lesson with a YouTube video in which we learned the lyrics and acted out the finger-play actions throughout the week.
#6 Mixing Colors
Once a toddler is familiar with the colors and can identify and name them correctly, it is time to add colors to science experiments. Working with primary colors, we have started to create a few experiments to make new colors. This week was all about yellow and blue making green. We did it with some water, food coloring, soap, and paint.
What Primary colors make new colors?
- Red and Yellow make Orange
- Yellow and blue make Green
- Blue and Red make Purple/Voilet
#7 Bubbles
Discovering air is one of the first science concepts that can be taught. Do this experiment if your child already knows how to blow out. Add a squirt of dish soap and some water to a bowl. Provide a straw and show your toddler how to blow to create bubbles.
Look at the colors the bubbles reflect. Can you hold one? Does it pop? Can you blow on them? What happens?
As a variation of this experiment, you can add watercolor paint to the solution and allow the colored bubbles to pop onto a piece of paper to create a work of art.
Bubble snake variation
Ready to level up bubbles? Cut the bottom off a plastic bottle. Cover the cut end with a sock or washcloth and secure it with a rubber band. Dip the fabric end into soapy water and blow through the mouth of the bottle to create a long bubble snake.
Safety note: Only let children blow out. Do not let them inhale through the bottle. This one is best with close adult help.
#8 DIY Lava Lamp
This experiment was one of Manu’s favorites. To create your own DIY lava lamp, you will need vegetable oil, water, food coloring, and effervescent tablets.
For our first try, we filled half of the glass cup with water and added food coloring (too much!), and the other half with vegetable oil. I crushed the effervescent tablet in many pieces because I knew my toddler would enjoy dropping the tablets into the glass.
Once the tablet hits the water, it starts to dissolve and create bubbles that travel upwards on the glass, passing through the oil and popping into the surface. Because the water doesn’t mix with the oil, you can visually see how these bubbles travel toward the surface and, once they pop, how the water travels back down.
For our second try, we used only 1/4 of water, much less food coloring, and much more vegetable oil in the glass. The lava lamp looked much better, as the colored water bubbles had more room to travel.
Cutting up the tablets into different pieces was a great idea. Manu loved creating the bubbles and enjoyed repeating them over and over.
#9 slime
Slime is a great tool for working on fine motor skills, and it is also a cool chemistry experiment. Similar to Oobleck, slime changes are composed when played with. It is solid but stretches or breaks. Toddlers, of course, won’t understand the science concept behind it, but they will enjoy playing with the material and doing their little experiments as they learn and understand how slime behaves. It is not like playdough; it is not like oobleck; it is its unique material.
I like using fluffy slime, like rainbow or white fluffy slime, with toddlers. Fluffy slime is less stretchy than other types, so it is easier for toddlers to handle.
Learn how to make rainbow slime
Learn how to make white fluffy slime
#10 Exploring light
Learning about light and dark, shadows and reflections are all science activities you can start exploring early on.
Make shadows using cutout woods or use your hands and a flashlight, use the sun to explore the light and it’s reflection. We have made colored bottles to explore the colors reflected on the floor, made apple-shaped suncatchers, and made a glow-in-the-dark sensory bottle.
#11 Skittles Rainbow
This one is extremely visual and always feels magical. Arrange Skittles in a circle around the edge of a white plate. Pour warm water into the middle until it touches the candy. Watch the colors spread toward the center.
Toddlers observe dissolving, color movement, and patterns.
Alexa Tip: Toddlers will want to touch it. Let them watch the rainbow first, then give them permission to mix it at the end. That “mixing moment” is often their favorite part.
#12 Magic Ink Color Discovery
This is a quieter experiment that combines art and discovery. Draw small dots, lines, or hidden designs with washable markers on a paper towel or coffee filter. Give your child water in a dropper or spray bottle. As they add water, the colors spread and blend.
Toddlers explore absorption, color movement, and fine motor control. It is a wonderful option for a slower morning when you want science without a giant cleanup.
#13 Walking Water Rainbow
This one is better for older toddlers and preschoolers because it takes a little patience. Line up several clear cups. Fill every other cup with colored water. Fold paper towels into strips and place one end in a full cup and one end in an empty cup. Over time, the water travels through the paper towel.
Alexa Tip: Set this one up before snack or lunch, then come back to it. Toddlers do better when they are not expected to stare at a slow experiment the whole time.
#14 Dancing Raisins
This is simple kitchen science with a big visual payoff. Fill a clear cup with sparkling water. Drop in a few raisins and watch them move up and down.
You can say, “The bubbles are carrying the raisins up.” Then let them watch as the raisins sink and rise again. For a fizzy twist, try popcorn kernels in a jar of water and baking soda, then pour in vinegar.
#15 Milk and Dish Soap
This experiment looks beautiful and feels a little like process art. Pour milk into a shallow dish. Add drops of food coloring. Dip a cotton swab in dish soap and touch it to the milk. Watch the colors move.
Safety note: This is not a tasting activity. Supervise closely with younger toddlers.
#16 Magnet Hunt
Magnets are perfect for toddlers because the “pull” feels surprising. Place objects on a tray or in a muffin tin. Invite your toddler to test which ones stick to a large magnet wand and which ones do not.
Use simple language: “It sticks.” “It does not stick.” “The magnet pulls it.”
#17 Lemon Volcanoes
This is a fresh twist on baking soda and vinegar fizz. Cut lemons in half and place them on a tray. Add a little baking soda and food coloring on top. Let your child poke and mix the lemon with a spoon or craft stick to create fizz.
Alexa Tip: The smell makes this one extra engaging. Toddlers love science they can smell, touch, and see.
#18 Shaving Cream Rain Cloud
Fill a clear jar with water. Add shaving cream on top as the “cloud.” Let your child drip blue-tinted water onto the shaving cream with a dropper. When the cloud gets heavy, the blue water falls through like rain.
Safety note: Use close supervision so shaving cream does not go into mouths or eyes.
#19 Floating Orange
Place an unpeeled orange in a bowl of water and watch it float. Then peel the orange and place it back in the water. It may sink.
Use simple language: “The peel has tiny air pockets.” “The orange floats with its jacket on.”
#20 Sound Shakers
This is a great one for toddlers who love music and movement. Fill empty containers with rice, beans, pasta, or beads and seal them tightly. Let your toddler shake each one and listen to the different sounds.
Ask: “Which one is loud?” “Which one is soft?” “Do these two sound the same?”
#21 Ramp and Roll
This is physics disguised as play. Create a simple ramp with cardboard, books, or a wooden board. Let your child roll toy cars, balls, and blocks down and observe what happens.
Change the height of the ramp and ask: “Which one goes faster?” “What happens if we make the ramp higher?” This is also sneaky early math: comparing, measuring, and predicting.
#22 Nature Soup Science
This is one of my favorite outdoor science activities because it uses what children naturally collect. Invite your child to gather leaves, flowers, sticks, and rocks and add them to a bowl of water. Let them stir, pour, smell, and observe.
Alexa Tip: This may not look like a formal experiment, but it is real science. Children are comparing, sorting, observing, and testing. If your child loves this one, you will find more ideas in my nature activities for toddlers.
#23 Bubble Foam
Bubble foam is a sensory science activity toddlers can explore with their whole hands. Blend water, dish soap, and food coloring until it becomes fluffy foam. Add it to a sensory bin and let your child scoop, squish, and explore. For a taste-safe version for little ones who still mouth everything, try my aquafaba foam.
Safety note: This activity is slippery. Keep towels nearby and supervise closely.
#24 Toy Wash Science
A toy wash sounds simple, but it is full of toddler learning. Set up a washing station with a bowl of soapy water, a bowl of clean water, a sponge or brush, and a towel. Let your child wash, rinse, and dry their toys.
This is a beautiful example of how science does not always need to be flashy. Sometimes it is just a child noticing that dirt comes off when they scrub.
#25 Pumpkin Volcano
This is a seasonal version of baking soda and vinegar fizz and it is perfect for fall. Hollow out a small pumpkin. Add baking soda, food coloring, and a squirt of dish soap inside. Pour in vinegar and watch the pumpkin bubble over.
Why science experiments matter for toddlers
NSTA — the National Science Teaching Association — supports hands-on, interactive science learning and emphasizes that young children need varied opportunities to explore and discover science concepts. These experiments deliver exactly that: real observation, real cause-and-effect, and genuine wonder.
Young children are natural scientists. Harvard’s Center on the Developing Child notes that early exploration builds the executive function skills — focus, curiosity, persistence — that support learning across every domain. A baking soda volcano is not just a fun activity. It’s a lesson in cause and effect, observation, and scientific vocabulary.
Setting up science experiments with toddlers: what works
Have low expectations for the “experiment” part and high expectations for the “toddler” part. They will immediately touch, squeeze, and taste whatever is in front of them. Work with this, not against it.
- Prepare for mess first. A tray or drop cloth saves your sanity.
- Use real vocabulary. “Dissolve,” “reaction,” “transparent” — toddlers absorb vocabulary used in context.
- Repeat experiments. Doing the same volcano three times in a week is scientifically excellent.
- Let them lead. If they want to mix things differently, let them. That’s science too.
- Ask open questions. “What do you think will happen?” beats explaining the answer before they’ve experienced it.
Best supplies for toddler science experiments
You do not need a fancy science kit to start. These are the supplies I use the most:
- Baking soda, vinegar, cornstarch, food coloring, and dish soap
- Droppers and squeeze bottles
- Clear cups, small bowls, and muffin tins
- Plastic trays and sensory bins
- Measuring spoons and ice cube trays
- Toy animals and magnifying glasses
- Towels. Always towels.
If you keep just a few of these at home, you can create dozens of toddler science activities without buying something new every time. Many of them double as materials for homemade playdough and sensory bins, too.
More science experiments to explore
- Classic Oobleck Recipe: The Ultimate Toddler Science Experiment
- Chocolate Oobleck Recipe
- Fizzy Cubes: Baking Soda Science for Toddlers
- Sink or Float Science Experiment
- Halloween Volcano Science Project
- Hot and Cold Science for Toddlers
- Baking Soda and Vinegar Fizz Experiment
Science experiment FAQ
What age can toddlers start science experiments?
Most experiments here work from age 2 and up. Oobleck and sensory-based science can start as early as 12-18 months with close supervision. More process-heavy experiments like the lava lamp are better from around 2.5-3 years.
What are the easiest science experiments for toddlers?
The easiest toddler science experiments are baking soda and vinegar fizz, sink or float, water color mixing, oobleck, ice melting, and bubble foam. They use simple materials and give toddlers immediate results.
How do you explain science to a toddler?
Use short, simple words. Instead of explaining chemical reactions, say, “The bubbles appeared when we mixed them.” Toddlers learn best by touching, watching, repeating, and hearing language connected to their play.
Do I need to buy science kits?
Not at all. Every experiment in this post uses things you likely already have: baking soda, vinegar, cornstarch, water, food coloring, and dish soap. No kit required.
What’s the best first science experiment for a toddler?
Oobleck. Two ingredients, completely non-toxic, demonstrates a fascinating property (non-Newtonian fluid), and provides 30+ minutes of exploration. Full recipe: Classic Oobleck Recipe.
How long do toddler science experiments take?
Setup: 5-10 minutes. Toddler engagement: 10-30 minutes depending on the experiment. Oobleck can go for an hour. The volcano is usually 10 minutes of intense excitement followed by requests to do it again immediately.
Science experiments by toddler age
Not every experiment works for every age. Here’s how to match the activity to where your toddler actually is developmentally.
Science for 12–18 month olds (baby science)
At this age, “science” is really sensory exploration — and that’s exactly right. Oobleck in a tray, water in a bin, ice cubes to hold and watch melt, bubbles to pop. The experiment is the material itself. Keep it simple, keep it supervised, and accept that everything will be tasted. Use only edible or food-safe materials at this stage.
Science for 2–3 year olds
Two and three-year-olds are ready for cause-and-effect experiments: adding vinegar to baking soda and watching it fizz, mixing colors, dropping objects to see what sinks or floats. They can follow one or two steps and have a genuine reaction to surprising outcomes. This is the prime age for the volcano, fizzy cubes, and color mixing experiments above.
Science for 3–5 year olds (preschool science)
Preschoolers can start to make predictions before an experiment (“I think the orange will sink because it’s big”) and compare their prediction to the result. They can also participate in simple measurement, counting, and observation journaling. More complex experiments like the DIY lava lamp work well at this age because they have the patience to watch what happens over a longer period of time.
Science vocabulary to use during experiments
One of the best things you can do during any science experiment with a toddler is use real scientific vocabulary in context. You don’t need to define the words formally — just use them while you’re narrating what’s happening. Over time, these words become part of your toddler’s working vocabulary:
- Dissolve: “The salt is dissolving into the water — it’s disappearing!”
- Absorb: “The paper towel is absorbing the water — sucking it up!”
- Reaction: “The baking soda and vinegar are having a chemical reaction — they’re making gas!”
- Transparent: “The water is transparent — we can see right through it.”
- Density: “The oil is less dense than the water, so it floats on top.”
- Observation: “What do you observe? What do you notice?”
- Hypothesis: “What do you think will happen? That’s your hypothesis.”
You don’t need to quiz them on these words or make it feel like a lesson. Just use them naturally and let the meaning come from the context. Toddlers are remarkable language absorbers when words are connected to real experiences.
Science and sensory play: how they connect
Many of the best toddler science experiments overlap directly with sensory play — oobleck, fizzy cubes, color mixing. That’s not a coincidence. Sensory play gives toddlers the hands-on exploration that makes science real, and science gives sensory play a framework that builds vocabulary and understanding. Explore our complete guide to toddler sensory activities for even more ideas that overlap with early science learning.
Building a science habit at home
You don’t need to do science every day — or even every week. But having a few go-to experiments that you can set up quickly makes it much easier to say yes when your toddler is in that curious, exploratory mood that science thrives in. Keep a small “science shelf” with baking soda, cornstarch, food coloring, and white vinegar within reach. That’s your entire science kit for the next two years.
The goal is not to produce a toddler scientist. The goal is to protect and nurture the curiosity they already have — the instinct to poke, wonder, test, and try again. These experiments do exactly that. And the mess washes off.
One simple trick: keep a small notebook in your science area and let your toddler “draw” their observations after each experiment. They can scribble what the oobleck looked like, or you can write down what they said (“it was cold and hard when I squeezed it and then it dripped”). This is early science journaling — and it reinforces the vocabulary and observation skills that are the real learning underneath all the fizzing and foaming.
Last Thoughts
Science can be a lot of fun, and as you can see, you can start even when they are toddlers. Allowing your toddler time and exposure to different materials and experiments helps them understand their world and gives them the confidence to experiment, explore, and gain a ton of new information when doing so. Don’t forget always to supervise any experiment or invitation to play.
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