45 Cool Chemistry Experiments, Demos, and Science Fair Projects

Don’t forget your safety equipment!

Chemistry experiments including using cabbage to test pH and breaking apart covalent bonds
We Are Teachers; Education Possible; Teaching Without Chairs

Bunsen burners, colorful chemicals, and the possibility of a (controlled) explosion or two? Everybody loves chemistry experiments! We’ve rounded up the best activities, demos, and chemistry science fair projects for kids and teens. Try them in the classroom or at home.

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Easy Chemistry Experiments and Activities for All Ages

These chemistry experiments and activities are all easy to do using simple supplies you probably already have. Families can try them at home, or teachers and students can do them together in the classroom.

Mix up some magic milk

Kids love this colorful experiment, which explores the concept of surface tension. This is one of our favorite chemistry experiments to try at home, since the supplies are so basic and the results are so cool!

Skittles form a circle around a plate. The colors are bleeding toward the center of the plate. (easy science experiments)
Toucan Box

Taste the Rainbow

Teach your students about diffusion while creating a beautiful and tasty rainbow. You’ll definitely want to have extra Skittles on hand so your class can enjoy a few as well!


Learn more: Skittles Diffusion

Colorful rock candy on wooden sticks
Growing a Jeweled Rose

Crystallize sweet treats

Crystal science experiments teach kids about supersaturated solutions. This one is easy to do at home, and the results are absolutely delicious!

Learn more: Candy Crystals

Make elephant-sized toothpaste

This fun project uses yeast and a hydrogen peroxide solution to create overflowing “elephant toothpaste.” You can also add an extra fun layer by having kids create toothpaste wrappers for their plastic bottles.

Girl making an enormous bubble with string and wire

Blow the biggest bubbles you can

Add a few simple ingredients to dish soap solution to create the largest bubbles you’ve ever seen! Kids learn about surface tension as they engineer these bubble-blowing wands.

Learn more: Giant Soap Bubbles

Plastic bag full of water with pencils stuck through it
Paging Fun Mums

Demonstrate the “magic” leakproof bag

So simple and so amazing! All you need is a zip-top plastic bag, sharp pencils, and some water to blow your kids’ minds. Once they’re suitably impressed, teach them how the “trick” works by explaining the chemistry of polymers.

Learn more: Leakproof Bag

Several apple slices are shown on a clear plate. There are cards that label what they have been immersed in (including salt water, sugar water, etc.) (easy science experiments)
Teaching With Jennifer Findley

Use apple slices to learn about oxidation

Have students make predictions about what will happen to apple slices when immersed in different liquids, then put those predictions to the test! Finally, have them record their observations.

Learn more: Apple Oxidation

Float a marker man

Their eyes will pop out of their heads when you “levitate” a stick figure right off the table. This experiment works due to the insolubility of dry-erase marker ink in water, combined with the lighter density of the ink.

Learn more: Floating Marker Man

Mason jars stacked with their mouths together, with one color of water on the bottom and another color on top

Discover density with hot and cold water

There are a lot of easy science experiments you can do with density. This one is extremely simple, involving only hot and cold water and food coloring, but the visuals make it appealing and fun.

Learn more: Layered Water

Clear cylinder layered with various liquids in different colors
Wonder How To

Layer more liquids

This density demo is a little more complicated, but the effects are spectacular. Slowly layer liquids like honey, dish soap, water, and rubbing alcohol in a glass. Kids will be amazed when the liquids float one on top of the other like magic (except it is really science).

Learn more: Layered Liquids

Giant carbon snake growing out of a tin pan full of sand

Grow a carbon sugar snake

Easy science experiments can still have impressive results. This eye-popping chemical reaction demonstration only requires simple supplies like sugar, baking soda, and sand.

Learn more: Carbon Sugar Snake

Two children are shown (without faces) bouncing balls on a white table
Come Together Kids

Make homemade bouncy balls

These homemade bouncy balls are easy to make since all you need is glue, food coloring, borax powder, cornstarch, and warm water. You’ll want to store them inside a container like a plastic egg because they will flatten out over time.

Learn more: Make Your Own Bouncy Balls

Pink sidewalk chalk stick sitting on a paper towel

Create eggshell chalk

Eggshells contain calcium, the same material that makes chalk. Grind them up and mix them with flour, water, and food coloring to make your very own sidewalk chalk.

Learn more: Eggshell Chalk

Science student holding a raw egg without a shell
Making Memories With Your Kids

Make naked eggs

This is so cool! Use vinegar to dissolve the calcium carbonate in an eggshell to discover the membrane underneath that holds the egg together. Then, use the “naked” egg for another easy science experiment that demonstrates osmosis.

Learn more: Naked Egg Experiment

Turn milk into plastic

This sounds a lot more complicated than it is, but don’t be afraid to give it a try. Use simple kitchen supplies to create plastic polymers from plain old milk. Sculpt them into cool shapes when you’re done.

Student using a series of test tubes filled with pink liquid
Education Possible

Test pH using cabbage

Teach kids about acids and bases without needing pH test strips. Simply boil some red cabbage and use the resulting water to test various substances—acids turn red and bases turn green.

Learn more: Cabbage pH

Pennies in small cups of liquid labeled coca cola, vinegar + salt, apple juice, water, catsup, and vinegar. Text reads Cleaning Coins Science Experiment. Step by step procedure and explanation.
Gally Kids

Clean some old coins

Use common household items to make old oxidized coins clean and shiny again in this simple chemistry experiment. Ask kids to predict (hypothesize) which will work best, then expand the learning by doing some research to explain the results.

Learn more: Cleaning Coins

Blow up a balloon (without blowing)

Chances are good you probably did easy science experiments like this when you were in school yourself. This well-known activity demonstrates the reactions between acids and bases. Fill a bottle with vinegar and a balloon with baking soda. Fit the balloon over the top, shake the baking soda down into the vinegar, and watch the balloon inflate.

Learn more: Balloon Experiments

Assemble a DIY lava lamp

This 1970s trend is back—as an easy science experiment! This activity combines acid/base reactions with density for a totally groovy result.

Four colored cups containing different liquids, with an egg in each
Feels Like Home

Explore how sugary drinks affect teeth

The calcium content of eggshells makes them a great stand-in for teeth. Use eggs to explore how soda and juice can stain teeth and wear down the enamel. Expand your learning by trying different toothpaste and toothbrush combinations to see how effective they are.

Learn more: Sugar and Teeth Experiment

Mummify a hot dog

If your kids are fascinated by the Egyptians, they’ll love learning to mummify a hot dog. No need for canopic jars; just grab some baking soda and get started.

Extinguish flames with carbon dioxide

This is a fiery twist on acid-base experiments. Light a candle and talk about what fire needs in order to survive. Then, create an acid-base reaction and “pour” the carbon dioxide to extinguish the flame. The CO2 gas acts like a liquid, suffocating the fire.

I Love You written in lemon juice on a piece of white paper, with lemon half and cotton swabs

Send secret messages with invisible ink

Turn your kids into secret agents! Write messages with a paintbrush dipped in lemon juice, then hold the paper over a heat source and watch the invisible become visible as oxidation goes to work.

Learn more: Invisible Ink

Set popcorn dancing

This is a fun version of the classic baking soda and vinegar experiment, perfect for the younger crowd. The bubbly mixture causes popcorn to dance around in the water.

Learn more: Dancing Popcorn Experiment

Shoot a soda geyser sky-high

You’ve always wondered if this really works, so it’s time to find out for yourself! Kids will marvel at the chemical reaction that sends diet soda shooting high in the air when Mentos are added.

Learn more: Mentos and Coke Experiment

Chemistry Science Fair Projects

All of these chemistry experiments are perfect for using the scientific method. Form a hypothesis, alter the variables, and then observe the results! You can simplify these projects for younger kids, or add more complexity for older students.

Tub of water with battery leads in it
Teaching Without Chairs

Break apart covalent bonds

Difficulty: Medium / Materials: Medium

Break the covalent bond of H2O into H and O with this simple experiment. You only need simple supplies for this one. Turn it into a science fair project by changing up the variables—does the temperature of the water matter? What happens if you try this with other liquids?

Learn more: Breaking Covalent Bonds

Measure the calories in various foods

Difficulty: Medium / Materials: Medium

Are the calorie counts on your favorite snacks accurate? Build your own calorimeter and find out! This kit from Home Science Tools has all the supplies you’ll need.

Fingerprint divided into two, one half yellow and one half black
Hub Pages

Detect latent fingerprints

Difficulty: Medium / Materials: Medium

Forensic science is engrossing and can lead to important career opportunities too. Explore the chemistry needed to detect latent (invisible) fingerprints, just like they do for crime scenes!

Learn more: Fingerprints Project

Use Alka-Seltzer to explore reaction rate

Difficulty: Easy / Materials: Easy

Tweak this basic concept to create a variety of high school chemistry science fair projects. Change the temperature, surface area, pressure, and more to see how reaction rates change.

Determine whether sports drinks really have more electrolytes than other beverages

Difficulty: Medium / Materials: Advanced

Are those pricey sports drinks really worth it? Try this experiment to find out. You’ll need some special equipment for this one; buy a complete kit at Home Science Tools.

Turn flames into a rainbow

Difficulty: Medium / Materials: Advanced

You’ll need to get your hands on a few different chemicals for this experiment, but the wow factor will make it worth the effort. Make it a science project by seeing if different materials, air temperature, or other factors change the results.

Supplies needed for mole experiment, included scale, salt, and chalk
Amy Brown Science

Discover the size of a mole

Difficulty: Medium / Materials: Medium

The mole is a key concept in chemistry, so it’s important to ensure students really understand it. This experiment uses simple materials like salt and chalk to make an abstract concept more concrete. Make it a project by applying the same procedure to a variety of substances, or determining whether outside variables have an effect on the results.

Learn more: How Big Is a Mole?

Aluminum foil bowl filled with bubbling liquid over a bunsen burner
Dunigan Science on TPT

Cook up candy to learn mole and molecule calculations

Difficulty: Medium / Materials: Medium

This edible experiment lets students make their own peppermint hard candy while they calculate mass, moles, molecules, and formula weights. Tweak the formulas to create different types of candy and make this into a sweet science fair project!

Learn more: Candy Chemistry

Lime green and orange homemade soap as part of a science experiment
Chemistry Solutions on TPT

Make soap to understand saponification

Difficulty: Medium / Materials: Medium

Take a closer look at an everyday item: soap! Use oils and other ingredients to make your own soap, learning about esters and saponification. Tinker with the formula to find one that fits a particular set of parameters.

Learn more: Saponification

Uncover the secrets of evaporation

Difficulty: Medium / Materials: Medium

Explore the factors that affect evaporation, then come up with ways to slow them down or speed them up for a simple science fair project.

Learn more: Evaporation

More Chemistry Experiment Science Fair Ideas

These questions and prompts can spark ideas for unique chemistry experiments:

  • Compare the properties of sugar and artificial sweeteners.
  • Explore the impact of temperature, concentration, and seeding on crystal growth.
  • Test various antacids on the market to find the most effective product.
  • What is the optimum temperature for yeast production when baking bread from scratch?
  • Compare the vitamin C content of various fruits and vegetables.
  • How does temperature affect enzyme-catalyzed reactions?
  • Investigate the effects of pH on an acid-base chemical reaction.
  • Devise a new natural way to test pH levels (such as cabbage leaves).
  • What’s the best way to slow down metal oxidation (the form of rust)?
  • How do changes in ingredients and method affect the results of a baking recipe?

Like these chemistry experiments? Don’t miss STEM Activities for Kids of All Ages and Interests.

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Looking for classroom chemistry experiments, school science fair projects, or fun demos you can try at home? Find them all here!