45 Clever Science Experiments for Kids That Are Easy to Set Up at Home
Hello, STEM! Use these simple DIY activities for science fairs, rainy days, and whenever you hear "I'm bored!"
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It's easy to get kids into STEM when you can give them something hands-on to do, especially if it's something they're really into. Do they love DIY art projects? Try making chromatography flowers, and show them how capillary action works. Are they interested in engineering "challenges?" Try telling them to make a bridge (or a tin-foil boat) that can hold pennies. Do they like seeing things fizz, explode, or rocket through the air? There are science experiments for that too.
All of these work because they're things kids can observe with their own eyes. Start them off with the scientific method: Give them a journal to record their observations, questions, hypotheses, experiments, results, and conclusions. Then, when they're ready, try one of these best at-home science experiments for kids, which cover topics like cover magnetism, surface tension, astronomy, chemistry, and physics, among others.
These experiments are mostly designed for preschoolers through elementary schoolers, with a couple that are either demonstrations or better for older kids. As always, safety counts: Adult supervision is required, and it might be necessary to wear goggles and lab coats or aprons if need be (some of these are messy). But that just means they'll look even more official as they go along on their STEM journey.
Floating Fish
This experiment is a lesson in solubility and density.
- In dry-erase marker, draw the outline of a fish (or octopus, or star, or whatever shape you'd like) on the bottom of a glass plate or tray. Make sure all the lines are fully connected by retracing the drawing as needed. Let the drawing dry for a minute or two.
- Fill a measuring cup with tap water. Place the pour spout just inside the corner of the dish and add water very slowly until it just covers the bottom. Be careful not to pour water directly onto your drawing or make splashes near it. The water will move toward your drawing, eventually surrounding it. Observe what happens. If the water splashes or it doesn’t work on your first try, empty the dish, erase the drawing with a paper towel, dry off the dish, and try again.
- Tilt the dish slightly from side to side and observe what happens.
What's going on? The drawing should float on the water and move around on the surface when the dish is tilted. Why? The ink in dry erase markers is engineered to be slippery. It’s made with a chemical that causes it to easily release from surfaces. (Permanent markers, on the other hand, are made with a chemical that makes the ink stick to surfaces. You can repeat the experiment with a permanent marker to see how it is different—just be sure not to ruin any good plates or trays!)
When the easy-release ink lets go from a surface, it floats for two reasons. First, dry erase ink isn’t soluble, which means it won’t dissolve in water. Second, dry erase ink is less dense than the water, so it becomes buoyant, meaning it can float.
Apple Oxidation
This is mini lesson in preservatives, with the goal of figuring out what is most effective in keeping an apple from turning brown. Cut up an apple, then grab different household liquids—sugar water, lemon juice, plain water as a control, and so on—then soak a slice of apple in each of the different substances. Lay them out on a tray, then observe how brown they get after three minutes, six minutes, and so on. Kids can also use the to practice the scientific method if they offer up hypotheses for which one will be most effective before they start.
Get the tutorial at Jennifer Findley »
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Grow an Avocado Tree
Caring for plants can be an easy introduction to Earth Science, and seeing roots sprout from an avocado pit has a big "wow" factor. To grow one at home, you can buy an AvoSeedo kit, which will help float the pit above the water—or use the DIY method, and suspend the put over the mouth of a jar with toothpicks. Either way, the pit has to be peeled first.
Chromatography Flowers
This is a fun one to try because it'll create something they might want to display in their rooms after the experiment is over. Take a coffee filter and draw stripes around it in marker. Then fold it up and dip the tip in water—and watch how the water travels up the filter and separates the marker lines into different pigments. The scientific word for this is called "chromatography," or the process of separating a solution into different parts (in this case, the marker ink).
Craft Stick Chain Reaction
Potential energy is stored energy, often due to an object's position, like a pom-pom resting on a not-yet-set-off chain reaction machine made of craft sticks. Kinetic energy is energy in motion, such as pom poms flying through the air! This one takes a lot of set up, but has a video-worthy result.
Brush, Brush!
Kids are told to brush their teeth, but this experiment really shows them why (and how to take better care of them).
- Write on sticky notes: Soda 1, Soda 2, Juice 1, and Juice 2. Place them in a row on a counter.
- Fill two glasses halfway with brown soda and place behind the Soda 1 and Soda 2 sticky notes. Fill two glasses halfway with lemon juice and place behind the Juice 1 and Juice 2 sticky notes.
- Carefully place one egg in the bowl. Squeeze a big dollop—about one tablespoon—of toothpaste on top of the egg and gently rub the toothpaste all around with your hands until the egg is completely covered in a thick layer of toothpaste. Repeat with a second egg.
- Gently submerge the toothpaste-covered eggs into the liquids: one egg in the glass labeled Soda 1 and the other egg in the glass labeled Juice 1. Wash and dry your hands.
- Gently submerge the remaining eggs, without toothpaste on them, in the remaining glasses: one in the glass labeled Soda 2 and the other in the glass of juice labeled Juice 2. Wash and dry your hands. Leave the eggs in the glasses for 12 hours.
- After 12 hours, remove the eggs from the glasses of soda one at a time. Rinse them in cool water and pat them dry with the towel. Place each egg by the sticky note of the glass it was in. Are the eggs the same or different colors?
- Remove the eggs from the glasses of juice one at a time. Rinse them under the faucet and pat them dry. Place each egg by the sticky note of the glass it was in. Feel the eggs gently. Does one feel stronger or weaker than the other?
- Write down your observations in your science notebook.
What's going on here? Teeth have an outer coating called enamel, which in this experiment is represented by the shells of the eggs. Toothpaste has many jobs: It cleans teeth, prevents stains, removes particles that can get stuck to teeth, and protects enamel. Dark liquids like cola, coffee, and tea can stain teeth, and acids like the kind in lemon juice can break teeth down and cause them to decay.
In this experiment, the egg without toothpaste will be brown and discolored from the soda, while the egg covered in toothpaste was protected from discoloration. In addition, the egg without toothpaste left in the lemon juice was worn down and soft to the touch, while the egg that was protected with toothpaste is stronger.
When a tooth is worn down, a cavity can form more easily. But the fluoride in toothpaste mixes with saliva to create a protective coating around tooth enamel. It helps keep teeth strong and cavity-free.
Water Walking
Rainbow-loving kids get a kick out of this experiment in capillarity and color-mixing. Start off with seven containers of water: Keep four of them clear, and then use food coloring to turn one yellow, one red, and one blue. arrange them in a circle, alternating clear and colored water. Take a paper towel, fold it into strips, and set it so that one end is in a colored liquid, and the other end is in a clear liquid, like a bridge. Repeat this so that there are bridges between all of the containers that are next to each other. Leave it for a few hours, and the colored water will "walk" over the bridges and into the clear containers, mixing colors so the clear containers will now be green, purple, and orange. (Like magic!)
Marshmallow Catapult
Time to send some marshmallows flying through the air—for science! Setting up a marshmallow catapult reinforces ideas about potential and kinetic energy. Kids can also experiment with how different variables can change the marshmallow's trajectory.
Color-Changing Invisible Ink
Give them their National Treasure moment—with a STEM-themed twist. A mixture of baking soda and water will create an "invisible ink" that can be revealed with a solution of turmeric and rubbing alcohol. Little scientists can also try different acid/base combinations to see which one makes the most dramatic result.
Grow Crystals
Crystal-growing kits are trendy right now, which means there's no better time to DIY your own (and even make something fun to decorate their rooms). When pipe cleaners, bent into different shapes, are left in a Borax solution overnight, they'll grow their own crystals. (A big caveat: Borax should be handled by adults, and kids need to understand that the end result is not edible even though it looks like it could be rock candy.)
Paper Bridge
The E in STEM stands for Engineering, and students will turn into engineers with this challege: How can they use paper to bridge two cups in a way that's strong enough to support as many pennies as possible? They can experiment with different ways of manipulating the paper to hold more pennies. (Hint: Fold it!)
Milk Bottle Xylophone
Chances are, they've clinked spoons against glasses before to hear what sounds are produced. Now to do that in a more scientific way!
- Arrange six glass jars or bottles, all the same size with no lids, in a line. What will each jar sound like when you tap it with a spoon? Tap each jar and observe the sound.
- Next, put water in each of the jars. Pour 1⁄4 cup (60 ml) of water into the first jar. Add 1⁄2 cup (120 ml) of water to the second jar. Continue in 1⁄4-cup increments, adding 3⁄4 cup (180 ml) of water to the third jar, 1 cup (240 ml) of water to the fourth jar, 11⁄4 cups (300 ml) of water to the fifth jar, and 11⁄2 cups (360 ml) to the sixth jar. Add a couple of drops of food coloring to each jar.
- What will each jar sound like? Make a prediction about which jars will have a higher pitch and which jars will have a lower pitch. Tap each jar with a metal spoon to see if the predictions are correct.
Sound waves are created by vibrations, which are back-and-forth movements that are repeated again and again. Pitch depends on the frequency of the waves, and how many are created each second. A high pitch is created by high-frequency sound waves, and can sound squeaky. A low pitch is created by low-frequency sound waves, and sounds deep and booming.
When a jar is tapped, it vibrates. The vibrations travel from the jar to the water to the air and eventually to your ears. The jars with more water had a low pitch because the sound waves vibrated more slowly because they had more water to travel through. A jar with no water in it makes the highest pitch because it has the least substance to travel through.
Shaving Cream Water Cycle
Give students a brush-up on the water cycle by setting shaving-cream clouds on top of a glass of water. Use a dropper to add in blue water, and when the clouds get saturated—blue rain.
Get the tutorial at Alice and Lois »
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Sticky Ice
Challenge your little scientist to lift up an ice cube with just a piece of string. It's possible ... with a little salt to help. Salt melts the ice and lowers the freezing point of the ice cube, which absorbs the heat from the water around it, making the water cold enough to re-freeze around the string.
Leaf Breathing
It's hard for kids to picture how plants and trees "breathe" through their leaves—until they see the bubbles appear on a leaf that's submerged in water. You can also teach them about photosynthesis by putting different leaves in different spots with varying levels of sunlight.
Hoop-and-Straw Airplane
We all remember how to fold those classic, triangular paper airplanes, but these hoop-and-straw airplanes fly way better (and straighter). Experiment by changing the length of the straw and the size of the hoops and see how it affects the flight.
Film Canister Rocket
Blast off! You don't need jet fuel to make these rockets go, just Alka-Seltzer tablets and baking soda, but they'll be amazed when they achieve lift-off! (Note: If you can't find old film canisters, tubes of Airborne work, too.)
Coin Inertia
Stack up about five or so coins on a piece of cardboard and place it over a glass of water. Then, flick the cardboard out from on top of the glass. Do the coins drop into the water, or ride with the cardboard? Due to inertia, they drop into the water—a very visual (and fun!) demonstration of Newton's First Law of Motion.
Coffee Ground Fossils
By making a salt dough with coffee grounds and pressing various shapes into it (toy dinosaur feet, seashells), kids can get a better understanding of how fossils are made. If you poke a hole in the top before it dries, the kids can hang their "fossils" up in their rooms.
Sunscreen Test
This experiment puts the A (art) in STEAM: Paint different designs on construction paper with different sunscreens, leave the papers out in the sun and compare the results. Then, hang your "conclusions" on your fridge.
Marisa (she/her) has covered all things parenting, from the postpartum period through the empty nest, for Good Housekeeping since 2018; previously, she wrote about parents and families at Parents and Working Mother. She lives with her toy-collecting husband and daughter in Brooklyn, where she can be found helping out her team at bar trivia or posting about movies on Twitter and Bluesky.
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