Thanks to common household ingredients, some ingenuity and our guide, these classic science experiments for kids make any day exciting. And we’ve rated each experiment from one to five sponges so you know the messiness factor ahead of time. Scroll down to see them all!

# Make a Sundial

A lesson in: Astronomy

Unravel the mysteries of time. Or at least figure out the basics by setting up a sundial outside. Take time each hour to check the sun’s positioning and make note of it so your sidekick can see the bigger picture.

Messiness Factor: One sponge

# Dry Ice Bubbles

A lesson in: Gas.

Dry ice is already cool enough on its own (yes, pun intended) but it takes science to turn them a rad overflow of bubbles. When you add water, it changes the temperature of the dry ice, causing the ice to go from solid to gas. That’s where the fog and bubbles come from! Head to crafty blog Simply Modern Mom to get the full tutorial. But be careful: Dry ice can cause serious skin burns, so make sure your kids are well supervised and know not to touch the ice.

Messiness factor: Three sponges.

photo: From Candy Experiments 2 by Loralee Leavitt/Andrews McMeel Publishing, LLC.

# Invisible Licorice

A lesson in: Light and perspective.

Did the candy melt or disappear? Your sweetums might think it’s magic, but it’s really all about how oil redirects light, causing half the candy to disappear! Click here for the instructions on how to recreate this mind-warping experiment.

Messiness factor: One sponge.

# Egg in a Bottle

A lesson in: Air pressure.

Your whistler has the basics of air pressure down just by using their mouth to blow. And now you can amaze them with this egg-cellent experiment. There is a little fire play involved (dropping a lit paper into the bottle), but that’s what causes the unbalanced air pressure, which pushes the egg into the bottle. Want to test it out? Head over to Steve Spangler Science for the tutorial.

Messiness factor: One sponge.

# Invisible Ink

A lesson in: Oxidation.

If your snacker has noticed how their apples have turned brown after being left out for too long, then they’ve seen oxidization in action (loss of electrons and nutrients when in contact with oxygen). Fortunately, lemon juice only oxidizes when in contact with heat. This method works with baking soda and milk too. Click here to find out how to write secret messages with your little spy.

Messiness factor: One sponge.

# Kid-Safe Lava Lamps

A lesson in: Density and intermolecular polarity.

These sound like big words for our little ones, but there’s an easier way to break it down. Water and oil won’t mix because they’re not the same “weight” or substance (just like clay and LEGOs won’t become one). Now add a drop of food coloring (which is heavier than oil) and a fizzy tablet and watch the air bubbles take coloring with them to the top. Head on over to S. L. Smith’s blog to see how it’s done.

Messiness factor: Two sponges.

photo: Melissa Heckscher

A lesson in: Germs

This germ-growing experiment, which will help kids understand how even the cleanest-looking surfaces (and hands) can be filled with germs, is one of the easiest science experiments for kids we've found. Get the fun and yucky instructions at kidsactivitiesblog.com.

# Taste Test

A lesson in: The five senses

After figuring out this simple experiment your sidekick will want to play Houdini with all her friends. All it takes is an apple, vanilla extract, and a cotton ball to pull one over on her tastebuds. Abracadabra!

Messiness factor: One sponge

# Rock Candy

A Lesson in: Crystallization.

Be careful: The water only has the power to make the sugar crystals “invisible” when it’s piping hot. After the water cools down and evaporates, the sugar turns back into a solid. And with a little help of your sugar-soaked string, the crystals will find a home to grow upon and become rock candy. Learn how to make your smart sweets with these instructions from the Exploratorium.

Messiness factor: Two sponges.

# S'more Solar Oven

A lesson in: Solar power

Harness the power of the sun to make your favorite campfire treat! With just a few common household items you can create an eco-friendly oven just for melting marshmallows and chocolate, plus you can teach kids about the power of the sun. Click here to learn how.

Messiness Factor: two sponges

# Make an Edible Water Bottle

A lesson in: Chemistry and specifically, spherification.

This futuristic experiment will leave your little scientist wanting to know more about chemistry. Quench her thirst for knowledge when you create an edible membrane around teaspoons of water to make these handy water “bottles.” The tutorial is in video form over at Inhabitat. Trust us, it’s as cool as it looks!

Messiness factor: one sponge

# Dissolving Candy Hearts

A lesson in: Chemistry

Explore the science of your child's fave Valentine's Day candy and use up those leftovers STAT. Toss them into warm water and wait (and watch, of course) to see what happens. Repeat the science experiment with cool water, veggie oil, milk or any other liquid and record what caused the candy to dissolve the fastest, which took the longest.

Messiness factor: one sponge

A lesson in: Chemistry.

Plain old fresh-squeezed lemonade is so last year. Boost the fun quotient and learn a simple science concept simultaneously when you recreate this edible Fizzy Lemonade drink from Learn With Play at Home. It’s super easy to mix and little sippers report it’s pretty tickly too. A great alternative to the baking soda-vinegar volcano, it shows kids what happens when an acid and base are mixed together.

Messiness factor: One sponge.

# Whirlpool in a Bottle

A lesson in: physics, weather science

This easy little experiment doesn't take much: just two empty and clear 2-liter bottles, a metal washer, water and some duct tape. Food coloring is optional. Fill one bottle with about two-thirds water. Place the washer on the bottle and line up the empty bottle on top of the water-filled one. Wrap the duct tape around the middle securing the two bottles together. Then, turn the bottles upside down. Does the water go straight down or do you see a mini whirlpool (Swirl the top or bottom a bit for a better effect)? The spinning water is called a vortex, and all tornadoes, hurricanes and typhoons are examples of air vortexes. Since you’re using water, this is an example of a whirlpool. As the water spins faster, it pushes to the outside of the bottle creating a hole in the middle. The air from the bottom of the bottle comes up the middle and the water from the top flows back down through the hole.

Messiness factor: Two sponges.

# Gumdrop Structural Challenge

A lesson in: Physics.

'Tis the season for gumdrops and this classic structural engineering challenge uses just two ingredients: toothpicks and candy. We’re particularly fond of this one from The Homeschool Scientist because it helps you explain what the concepts (engineering, load distribution, physics, shape comparison) are to your kiddos while they are building it. doing it. Visit The Homeschool Scientist to get going. And click here for five more gumdrop-themed challenges.

Messiness factor: One sponge.

# Exploding Pumpkins

A lesson in: Chemical reactions.

By now you've probably parented for long enough to have tried the good ol' baking soda and vinegar volcano more than a few times. This fall-themed take on the classic, from Little Bins for Little Hands, is a scientific exploration that will make a mess in the most magnificent way possible!

Messiness factor: Five sponges.

# The Science of Fall Colors

A lesson in: Botany, plant life cycles.

Why do leaves change color in the fall? That's a tricky one to explain to your child. That is, without the help of a hands-on experiment to do the "talking." If you're not sure where to start, check out this simple exploration from How We Learn

Messiness factor: Zero sponges.

photo: Melissa Heckscher

# Make a Baking Soda & Vinegar "Steam" Powered Boat

A lesson in: Chemical reactions.

Sure, anyone can do the old baking soda and vinegar volcano, but what about creating a boat that is propelled by this classic chemical reaction? Keep your little Einsteins busy this afternoon with this cool experiment that doesn't require a lot of prep. Get the step-by-step here

Messiness factor: Three sponges.

# Salt Crystal Feathers

A lesson in: Evaporation. And also awesomeness.

You’ve probably tried a salt crystal growing kit at some point in your life (5th grade Science Fair perhaps?) but Schooling a Monkey takes the idea to a new level with these Salt Crystal Feathers. This awe-inspiring project is deceptively simple and inexpensive to achieve, and requires just a wee bit of patience to see the results—kids will love checking in on the progress. Visit Schooling a Monkey now to get started.

Messiness factor: One sponge.

# Soda Blasting Experiment

A lesson in: Chemistry, pressure and release of pressure.

Definitely one you'll want to do outside, this experiment makes baking soda + vinegar mere child's play. Step it up with this Mentos + soda experiment: head to Steve Spangler for all the need-to-know details on this engaging experiment.

Messiness factor: Three (very epic) sponges.

photo: Shelly Massey

# Melting Rates

A lesson in: Solar science and absorption.

Different colors have different heat absorbing capacities. Black has the greatest heat-absorbing capacity, which results in ice melting quicker than on white, which reflects the most light. Learn how to observe and report on which colors affect ice’s melting rates here on Curiodyssey. Get more sidewalk science ideas here.

Messiness factor: One sponge.

# Make Water Float

A lesson in: Air pressure.

Can you make water float? We bet you can. No, you don’t need to be a wizard or a witch. You don’t need to cast a spell. There’s nothing magic about it at all, in fact. You can make water float using good, ol’ fashioned, awesome science. The “trick” to this experiment is air pressure. Get everything you need and the how-to, right here, thanks to Mike Adamick and his book, Dad's Book of Awesome Science Experiments.

Messiness factor: Two sponges.

# Crystal Egg Geodes

A lesson in: Molecular bonding and chemistry.

This grow-your-own experiment that lets you grow crystals inside an egg shell. Be sure to get alum powder that contains potassium, or else you won't get any crystal growth. Adding drops of food dye to the growing solution yields some super cool crystals. A perfectly formed geode takes about 12-15 hours to grow, making this a great weekend project. Check out more of Art and Soul's gorgeous eggs over at their blog!

Messiness factor: Four sponges.

# Water Density Rainbow

A lesson in: Water density.

With just a spoonful of sugar and some food coloring, you can make water more or less dense, and with a little practice, you can make a rainbow in a jar! Check out how to do it here! If you like rainbows, click here for five other ways to make one in your own home.

Messiness factor: Two sponges.

photo: Photo: S. Massey

# Walk on Eggs

A lesson in: Weight distribution.

How can you walk on eggs without breaking them? Steve Spengler shows us how and teaches an awesome lesson on how an egg’s unique shape gives it tremendous strength, despite its seeming fragility. Check out this play-by-play to get started.

Messiness factor: One to three sponges, depending on the state of the eggs in the end!

# Make Elephant Toothpaste

A lesson in: Chemistry and the exothermic process <<<impress your kids!

If you’ve ever wondered how elephants keep their tusks clean, we’ve got the answer. They use elephant toothpaste! Find out how to mix your own and figure out the science behind this dynamic exothermic (heat releasing) reaction from Asia Citro at Fun at Home With Kids. Our favorite part? That you get to throw in some sensory playtime after the action’s over.

Messiness factor: Three sponges. Maybe four.

photo: Amber Guetebier

# Bending Water with a Comb

A lesson in: Electrical currents and static electricity.

This static electricity science experiment couldn't be any easier. In fact, other than a balloon or going down the slide, it might be the easiest way to teach kids about electrical currents. And, you can impress them with your wizarding skills once before you reveal the science behind it. Click here to get the step-by-step.

Messiness factor: One sponge.

A lesson in: Solar science, tracking how the earth moves around the sun/

See what happens when you set up toys on paper in the sun, and try tracing their shadows at different times of the day. You can draw right on the sidewalk with chalk, too. Pick toys with distinctive outlines to make it easier. For more science fun in the sun, click here.

Messiness factor: One sponge.

# Glowing, Smoking Bubbles

A lesson in: Sublimation.

When a substance passes directly from a solid phase to a gas phase without ever becoming a liquid, it sublimates. Add a little dry ice to bubble solution and the contents of an activated glow stick and get ready to rock the glow-in-the-dark scene in your neighborhood. Owlcation whipped up this awesome experiment to create glowing bubbles, and The Maker Mom thought to add dry ice to the same experiment here. The bubbles are out of this world—they glow and rise from the smoke. Naturally, we recommend an adult to handle the dry ice (skin contact can burn) and supervise this experiment.

Messiness factor: Three sponges.

# Regrow Leftovers

A lesson in: Photosynthesis and plant science.

Insert a little plant science into the mix by re-growing food from scraps. Think onions, potatoes, and lettuces for this one (psst… green onions are a super easy, fast option). Get the low down on all that recycled goodness at Mrs. Happy Homemaker. Since plants need water and sunlight to grow, exposing scrap roots to that winning combo helps them recharge.

Messiness factor: Two sponges.

# Magnetic Cereal

A lesson in: Magnetism.

You’ve probably seen the label that says “fortified with iron” on your cereal box, but how much iron is actually in your cereal? Is there enough to cause a magnetic reaction? This super easy experiment doesn’t require too many fancy ingredients (cereal + magnet) which means you and the kiddos can try it right away. The results may surprise you! Get the how-to at Rookie Parenting and get started!

Messiness Factor: Two sponges.

A lesson in: Polymers.

Is it a liquid or solid? The answer is both! This DIY slime—made from glue, borax and water—is also known as a polymer (molecules that can stick close together to be a solid or spread apart and take liquid form). And it’s all thanks to borax, which acts as a binder to prevent the glue from going completely liquid. Check out Explorable’s recipe on mixing the ingredients. Prolong the life of your goo by keeping it in an airtight container in the fridge.

Messiness factor: Three sponges.

# Turning Pennies Green

A lesson in: Chemical reactions.

It happens to the Statue of Liberty and it happens to the change in your pocket! Create your own home lab with just a few household ingredients (this experiment will literally cost you just pennies). It’s also a chemical reaction with very non-toxic ingredients, so it’s safe and fascinating even for young kids. Click over to Buggy and Buddy to get the simple how-to.

Messiness factor: One sponge.

# Film Canister Rocket

A lesson in: Rocket science.

Like the popular baking soda and vinegar experiments, this film canister rocket literally takes it to the next level by using that creation of gas and energy to jet off into the sky. If your explorer has seen videos of mountain tops getting blown off during a volcanic eruption, this science project is pretty much any space lover’s version. Get the building instructions over at kids science activity blog The Science Kiddo.

Messiness factor: Three sponges.

# Potato Power

A lesson in: Chemical to electrical energy.

When these nails and copper wires collide, heat is generated (psst ... heat is a result of expended energy, so you can explain to your little runner why he feels warmer after a race around the house). But with some potato magic, the properties of the nail and copper stay separated, allowing the heat to become the electric energy needed to power up your devices. Build your own potato battery with this tutorial from Wiki How .

Messiness factor: One sponge.

# Disappearing Egg Shell

A lesson in: Chemistry.

Can you and the kiddos solve the mysterious case of the disappearing egg shell? Following the simple how-to at Go Science Kids, you’ll learn the step-by-step and talking points about the process along the way. Warning! Although it’s totally non-toxic, toddler aged kids will be tempted to squeeze the egg at the end so make sure it’s a supervised experiment. Visit Go Science Kids to get cracking!

Messiness factor: One sponge.

# Baking Soda and Vinegar Volcano

A lesson in: Basic chemistry.

When it comes to reactions, this project has us watching our tot's face for the big, explosive reveal. The fizzy overflow is a result of combining baking soda and vinegar (and red food coloring for the cool lava effect), which makes carbon dioxide turn into gas. It’s a real volcano on a small scale. Click here for complete instructions.

Messiness factor: Four sponges.

# Fishing for Ice

A lesson in: Freezing/temperature.

Children living in snow-covered cities might witness their neighbors salting the driveway. Well, while that is definitely not for fun, this experiment is. Salt lowers the freezing point of ice so it melts, but it won’t be able to freeze unless it’s cold enough. See how activity blog The Science Kiddo made a clever game with this knowledge here.

Messiness factor: Two sponges.

# Cloud Jars

A lesson in: How clouds hold water.

Let your imagineers pretend shaving cream is a cloud that holds colorful raindrops. As they squeeze more and more food coloring, their “cloud” will soon release the excess below—just like how real clouds get too heavy and let the rain loose on a gloomy day. Learn how to re-create this weather experiment here.

Messiness factor: One sponge.

# Dyed Plants

A lesson in: Capillary action.

Find out how plants “drink” water with some food coloring. Use carnations, roses, or stalks of celery submerged in the colored water and watch the liquid slowly seep through the plant’s “veins” and towards the leaves. Keep an eye out -- you could have a very colorful bouquet just after the first day. Get the rundown by Dad’s Book of Awesome Science Experiments over here.

Messiness factor: One sponge.

# Dancing Oobleck

A lesson in: Sound waves.

The word “oobleck” comes from a Dr. Seuss story where a young boy must rescue his kingdom from a sticky substance. But the neat part of this experiment is how oobleck reacts to vibrations. Put the oobleck over a subwoofer (on top a cookie sheet!) and watch it dance to difference frequencies. Your dancer will see how sound isn’t just about volume! Check out more of this awesome experiment from Tammy of Housing a Forest.

Messiness factor: Five sponges.

A lesson in: Static electricity. (Or weather science.)

Lightning is essentially electrons moving uber fast between the sky and the earth—and with a few simple materials, you can use homemade static electricity (the reason behind your hair sticking up when you rub a balloon or go through a tunnel slide super fast) for DIY lightning. Figure how to recreate a family-friendly version of this spark by visiting activity blog Learn Play Imagine.

Messiness factor: One sponge.

—Christal Yuen & Amber Guetebier

Feature photo: iStock

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