All Science Fair Projects
1000 science fair projects with complete instructions.
73 Science Projects for 3rd Graders
Looking for ways to develop a lifelong love of learning in 3rd graders? Our handpicked list of 3rd grade science projects is designed to do just that!
3rd Grade Science Project FAQ
What are some easy 3rd grade science fair projects.
Any one of these easy 3rd grade science fair projects will teach you important scientific concepts and help you have fun while learning. An easy science fair project is a great way to introduce the wonders of science to 3rd graders!
Preserving Flowers with Sugar
Bacteria on Our Hands
Growing Your Own Yeast Fungus
Magic Milk Painting
Swimming Raisins
Making Oobleck: Liquid or Solid?
Sparkling Rainbow Crystal
Explosive Elephant Toothpaste
Colors of Skittles Experiment
Balancing a Ball in Air
Science fair project details right above the FAQ!
What is the best 3rd grade science project ever?
We love the Bacteria on Our Hands science fair project for 3rd graders. It's a great way to introduce 3rd graders to bacteria, tiny living things we can't see until we grow a bunch of them on a special plate called an agar plate.
If you're looking for more 3rd grade science projects, check out the 3rd grade science fair projects at the top of this page!
Check out more Best Science Fair Projects →
What are some cool 3rd grade science fair projects?
Get ready to be amazed by these super cool science projects for 3rd graders! With just a few simple things, you can be fascinated by science and have tons of fun with these cool 3rd grade science projects!
What are 5 testable questions for 3rd grade?
A testable question is a question that we can answer through a science experiment. To do this, we do a control science experiment, then we change one thing in the experiment to see how it affects what happens. This is how we can discover the answer to our question!
What makes a cloud form?
Can drink and food taste different just by changing its color?
Does the color of light affect photosynthesis?
Does temperature affect seed sprouting?
What makes popcorn pop?
Here are more testable questions along with their science projects →
What are the top 10 science projects for 3rd grade?
These are our top 10 science projects for 3rd grade, with projects from Biology, Chemistry, Physics, Engineering and Earth Science. These projects can be used as science fair project ideas or as a fun experiment to explore different areas of science!
Colorful Temperature
How Soil Affects Pinto Bean Growth
Jiggly Earth: Exploring Liquefaction
Growing Crystals in Different Temperatures
Make Your Own Anemometer
Science project details right above the FAQ!
Can I do a 3rd grade science fair project in a day?
Yes! Quick experiments can be a great option for a science fair project! If you want to explore quick reactions, we have science project ideas on various topics to get you started.
Acid-base reactions: Mixing acids with bases quickly makes carbon dioxide gas!
Make a rocket fly sky high with just baking soda and vinegar! Rocket Film Canisters
Chromatography reactions: Separate out colors!
Did you know that some Skittles have a secret rainbow hiding inside them? Colors of Skittles Experiment
Heat reactions: Heat speeds things up!
Do you want to find out which color candle burns the fastest? Which Candle Burns the Fastest?
What are some hands-on ways to find inspiration for my science fair project?
There may be free admission days or free passes to a science museum near you! Check your local library for free museum passes, nearby science museums for free entrance days and your credit card for offers.
Find a science museum near you and prepare to be awed by all that you can learn there! I always learn something new and am inspired whenever I go to a science museum!
How do I start a science fair project?
What should I do after I have a science fair project idea?
How do I make a science fair board?
What is the scientific method?
What is the engineering design process?
Where can I find a science fair competition?
The www Virtual Library: Science Fairs website also has a collection of science fairs from all over the world, as well as national, state, regional, local, and virtual competitions!
- Grades 6-12
- School Leaders
Check Out Our Latest Giveaways! Win a Classroom Garden, Field Trips, and More
Every product is independently selected by our team of teacher-reviewers and editors. Things you buy through our links may earn us a commission.
75 Terrific 3rd Grade Science Projects Anyone Can Do
Engage students in the classroom, or prep for the science fair!
Want to see your students’ eyes light up? Tell them they’re going to do an experiment! These 3rd grade science projects are easy enough for any classroom or kitchen, and they’re full of science concepts kids need to learn.
To make things even easier, we’ve rated every one of these 3rd grade science experiments based on difficulty and materials:
Difficulty:
- Easy: Low or no-prep experiments you can do pretty much any time
- Medium: These take a little more setup or a longer time to complete
- Advanced: Experiments like these take a fairly big commitment of time or effort
- Basic: Simple items you probably already have around the house
- Medium: Items that you might not already have but are easy to get your hands on
- Advanced: These require specialized or more expensive supplies to complete
3rd Grade Science Fair Projects
3rd grade stem challenge projects, magnet and electricity science experiments for 3rd grade, more 3rd grade science projects and activities.
Use these ideas to build a 3rd grade science fair project. Form your own hypothesis, alter the variables, and see what happens!
1. Discover the chemistry of slime
Difficulty: Easy / Materials: Medium
Kids adore slime, and it’s actually a terrific way to teach them about polymers. Learn the basics of slime chemistry, then experiment with the formula to make your own unique concoctions.
2. Make sun prints to display
You’ll need special sun-print paper for this project, but it’s inexpensive and easy to find. Kids learn about chemical reactions as they use the power of the sun to create unique works of art.
3. Experiment with ice, salt, and water temperature
Difficulty: Easy / Materials: Basic
This simple experiment requires only water, ice, salt, and a thermometer. Your 3rd grade science class can explore how ice and salt affect the temperature, a simple but effective lesson on heat transfer and freezing points.
Learn more: Ice, Salt, and Temperature Experiment
4. Learn about chromatography
Play around with colors, mix them together, and then use a little science magic to pull them apart again. This chromatography science project requires only simple supplies like coffee filters and markers.
Learn more: Chromatography
5. Understand the science behind bath bombs
Difficulty: Medium / Materials: Medium
Bath bombs certainly make bath time more fun, but what makes them work? Explore chemical reactions and get squeaky clean all at the same time!
Learn more: Bath Bomb Science Experiment
6. Investigate the effects of erosion
Compare the effects of “rain” on hills of bare soil vs. those covered with grass. Have your 3rd grade science students predict which they think will stand up to erosion better and then test their hypotheses.
Learn more: Erosion Experiment
7. Give flowers a glow-up
This one will make kids’ eyes pop out of their heads! Use highlighters and a black-light flashlight to reveal the vascular system of flowers.
Learn more: Plant’s Vascular System
8. Grow bacteria from common surfaces
There’s never been a better time to learn about the way germs spread! Take samples from a variety of surfaces, then watch bacteria grow in petri dishes just like grown-up scientists.
Learn more: Growing Bacteria
9. Take friction for a ride
Your students will love pulling their way across the floor as they discover more about friction and its effects on motion. Build your own “sled” or use a premade box or tray.
10. Go green with recycled paper
We talk a lot about recycling and sustainability these days, so show kids how it’s done! Recycle old worksheets or other papers using screens and picture frames.
Learn more: Recycled Paper
11. Filter sediment from dirty water
Explore sediments and water filtration with this easy 3rd grade science experiment. It’s a fun way to learn more about the water cycle.
Learn more: Water Filtration Experiment
12. Put together a compost bottle
Learn about the decomposition of food and how composting can provide nutrients for growing more food with this easy earth science project.
Learn more: Soda Bottle Compost
13. Sprout new potatoes
Potatoes grow from tuberous roots, and under the right conditions, new shoots appear from those roots. This 3rd grade science experiment explores the biological science behind cloning.
14. Keep apples from turning brown
What’s the best method to keep sliced apples from turning brown? Find out with this popular 3rd grade science project.
Learn more: Prevent Apple Browning
15. Fizz it up with antacid
Fizzy fantastic fun! Learn about chemical reactions by mixing water and effervescent antacid tablets to see what happens, comparing the time it takes for whole tablets and small pieces.
16. Drop objects to learn about gravity
Do heavier objects fall faster than lighter ones? Try this hands-on gravity activity for 3rd graders to find out!
Use these STEM challenges as the basis for science fair project ideas, or try them as in-class science activities your 3rd graders will love!
17. Design a candy-delivery machine
Learn about inclined planes with this fun simple-machines project. Kids can get creative and develop any kind of delivery system they like! Plus, 3rd grade science projects that end with a nice handful of candy can’t be beat!
Learn more: Candy Machine
18. Determine the most waterproof roof
Calling all future engineers! Build a house from LEGO, then experiment to see what type of roof prevents water from leaking inside.
Learn more: Waterproof Roof STEM Challenge
19. Run marble races with pool noodles
Crack open a pool noodle or two and create your own marble racetracks. Experiment with angles, force, and surface materials to find the fastest way to get the marble to the bottom. ( Find more fun ways to use pool noodles in the classroom here. )
Learn more: Pool Noodle Marble Races
20. Build a better umbrella
Challenge students to engineer the best possible umbrella from various household supplies. Encourage them to plan, draw blueprints, and test their creations using the scientific method.
Learn more: Best Umbrella STEM Challenge
21. Construct a marshmallow catapult
Fling some sweet treats in the name of science! All you need is an old tissue box, pencils, rubber bands, and a few other supplies to learn about trajectory, air resistance, gravity, and more.
Learn more: Tissue Box Catapult
22. Blow through a water whistle
Learn about the science of sound with this easy experiment. Kids will love building their own whistles from straws and a glass of water.
Learn more: Water Whistle
23. Step through an index card
With carefully placed scissor cuts on an index card, you can make a loop large enough to fit a (small) human body through! Kids will be wowed as they learn about surface area.
Learn more: Index Card Experiment
24. Construct a Hero’s engine
Difficulty: Medium / Materials: Basic
Sir Isaac Newton came up with rules about how things work in the world. One of these rules is called Newton’s third law. It says that “for every action, there is an equal and opposite reaction.” Do an experiment with your 3rd graders to learn more about this rule!
25. Model the effect of air drag
To learn about the role of drag in flight, students can fold paper planes in different styles and observe how these changes affect the distance and flight pattern of the planes. Turn this 3rd grade science project into a fun competition to see which plane flies the farthest or stays in the air the longest.
26. Put together an anemometer
This very simple weather instrument is easy enough for kids to build, allowing them to observe and think like a real meteorologist.
These shocking (OK, not literally!) electricity experiments will fit nicely into many 3rd grade science curriculum programs. Give them a try in the classroom, or encourage an interest in science at home.
27. Assemble a simple circuit
To test the conductivity of different materials, your students can use a simple electric circuit. Invest in a few of these inexpensive gadgets to allow for all kinds of 3rd grade science projects.
Learn more: Simple Circuits
28. Turn a safety pin into a circuit
Looking for an even easier simple circuits project? This one requires only a few supplies you can grab at the hardware store and an ordinary everyday safety pin.
29. Investigate how liquids affect magnets
Are magnets equally effective in water? What about oil or a thicker liquid like, say, a milkshake? This would make for an easy 3rd grade science fair project that’s fun too.
30. Ask a magnet to dance
This is so cool! Make a magnet dance without touching it in this activity that’s part STEM challenge, part magnet experiment, and 100% amazing.
31. Capture lightning in a bottle
Well, it’s not quite that dramatic, but this cool electricity experiment for 3rd grade will still wow your students.
32. Separate salt and pepper with static electricity
When you mix up salt and pepper, you’d think it would be almost impossible to separate them again. But using a little static electricity and a plastic spoon, it’s surprisingly simple.
Learn more: Separate Salt and Pepper
33. Explore static electricity with jumping goop
Your students have probably tried rubbing a balloon on their head to create static electricity with their hair. This experiment is even cooler to see, as a mix of cornstarch and oil seems to leap off the spoon in front of their eyes!
Learn more: Static Electricity Goop
34. Predict the distance of lightning
This weather science experiment never fails to impress. Use a stopwatch to measure the difference between the flash and the sound of lightning and thunder, then calculate the distance between you and the strike.
35. Find your way with a DIY compass
Here’s an old classic that never fails to impress. Magnetize a needle and float it on the water’s surface—it will always point north.
Learn more: DIY Compass
36. Defy gravity with magnets and paper clips
Magnets are always a hit in the classroom. Use this simple experiment to discover more about gravity and the effects of magnets on metal objects.
Learn more: Gravity Activity With Paper Clips
These science experiments for 3rd graders explore all sorts of concepts, from the laws of motion to earth and planetary science and beyond.
37. Flick pennies to learn about inertia
This is one of those science experiments that kind of looks like magic, but it’s really all about the laws of motion. It might take a little practice to get the index card flick just right, but the results are always cool!
Learn more: Inertia Science With Pennies
38. See the temperature rise in a chemical reaction
When iron meets oxygen, rust forms. Use vinegar to remove the protective coat from steel wool and watch the temperature rise from the chemical reaction.
Learn more: Simple Chemical Reaction Experiment
39. Float an iceberg
Use a balloon to make an iceberg, then float it in a dish of water to learn how much you can see above and below the waterline. Try experimenting with salt water to see how the density changes things.
Learn more: Make an Iceberg
40. Take a Play-Doh core sample
Learn about the layers of the Earth by building them out of Play-Doh. Then students can take a core sample with a straw. ( Love Play-Doh? Get more learning ideas here. )
Learn more: Core Sampling
41. Spin a disappearing color wheel
Color a paper disk with the six primary and secondary colors. Then thread a string through the middle and make it spin. The colors will seem to disappear!
42. Crystallize some pretty fall leaves
Every kid loves making crystals. In this 3rd grade science project, learn about supersaturated solutions by crystallizing some colorful fall leaves. Then use them as fall classroom decor!
Learn more: Salt Crystal Leaves
43. Find a robot’s center of gravity
Print out, cut, and color this free paper robot. Then glue some coins to the back and have your students try to find its center of gravity.
Learn more: Balancing Robot
44. Make your own bouncing bubbles
Have your 3rd grade science students put on gloves and watch the bubbles bounce! Then encourage them to experiment with their own bubble solution. Try different soaps, mixing up the ratios to make the strongest bubble possible.
45. Project the stars on your ceiling
Use the video lesson in the link below to teach 3rd grade science students why stars are only visible at night. Then create a DIY star projector to explore the concept hands-on.
Learn more: Star Projector
46. Blow bubbles inside bubbles inside bubbles
If there’s a more fun 3rd grade science project about surface tension than bubbles, we haven’t found it yet! Create a soap solution by using dissolved sugar and discover more about elasticity and volume as you blow bubbles inside bubbles inside bubbles …
47. Use water balloons to explore buoyancy
Fill water balloons with different solutions (oil, salt water, fresh water, etc.) and place the balloons in a large bucket of water to see if they sink or float. This is a cool project to do with your 3rd grade science class on the playground on a sunny day.
Learn more: Balloon Density
48. Learn how water temperature affects density
Looking for a simple, quick, and colorful science experiment? This one just requires some mason jars, hot and cold water, and food coloring. Kids will be amazed at the results!
Learn more: Water Density Experiment
49. Dissolve cups to learn about types of change
Teach your 3rd grade science class about the differences between physical and chemical changes with this quick and easy experiment involving Styrofoam cups.
Learn more: Dissolving Cups
50. Turn crayons into rocks
Demonstrate the effects of heat and pressure on crayon shavings to explain the different types of rocks to students. It’s a colorful intro to geology!
Learn more: Crayon Rocks
51. Stab a straw through a potato
Plastic straws may seem flimsy, but by using the power of air pressure, you can make one strong enough to stab all the way through a potato!
Learn more: Straw Potato
52. Shake up some ice cream
Get kids up and moving when they shake their way to ice cream, made from scratch using ice and plastic zipper bags! Talk about heating and cooling as well as condensation while you enjoy your snack.
Learn more: Make Ice Cream in a Bag
53. Watch pine cones open and close
Pine cones can sense changes in humidity and adjust their scales in response. Gather several pine cones, glass containers, tweezers, and both hot and cold water to conduct a fun experiment to discover what makes pine cones open and close.
Learn more: Pine Cone Experiment
54. Make butter slime
Difficulty Easy / Materials: Basic
While this slime recipe doesn’t use actual butter, the end consistency is just plain awesome! Have fun getting creative with colors.
55. Create a solar oven
Learn about solar radiation while making a tasty treat. Aside from the ingredients to make s’mores, all you need is some tinfoil, plastic wrap, and a beautiful sunny day.
56. Mix up some chalk paint
Difficulty Medium / Materials: Medium
You might think you’re baking at first since you’ll need water, cornstarch, food coloring, a measuring bowl, and a muffin tin. Really though, you’ll be making sidewalk paint chalk! Grab some foam brushes and head outside on a nice day to experiment with it.
57. Poke pencils through water
Want to show your students how polymers work while amazing them in the process? Then this is the perfect simple experiment for you. All you’ll need is a bag, some water, and some pencils.
58. Have a blast with Mentos and coke
Before getting started, have your students create funnels from card stock. Once you’re ready to try the experiment, you’ll want to head outside because things might get messy. Drop the Mentos into the top of a coke bottle using the funnel and then watch the explosion!
59. Whip up some elephant toothpaste
This is an experiment you’ll want to perform yourself for the kids to watch. It’s a great way to teach the kids about exothermic reactions. Kids will be amazed at the super-sized reaction.
60. Erupt some fun
You’ll need baking soda, vinegar, dish soap, and food coloring as well as some type of plastic volcano form. This classic science experiment serves as an example of an acid-base reaction. Add in some plastic dinosaurs to really liven up the scene!
61. Mix an egg with some vinegar
This is a great way to safely demonstrate a chemical reaction. Simply have students drop an egg in a cup of vinegar and then wait a few days to see the progression. They’ll be amazed by the egg’s transformation into a bouncy ball of sorts!
62. Make giant bubbles
This is another bubble project. Kids will get a kick out of seeing the larger-than-life bubbles their new wand can create. Be sure to assist with the hot-glue gun so little hands don’t get burned.
63. Decode messages
Kids will definitely enjoy getting to play detective. This one requires a few more supplies than some of the others on our list.
Learn more: Color-Changing Invisible Ink
64. Make a lemon volcano
This is another variation on the classic volcano science experiment. We especially love how minimal the materials are for this one. Grab some lemons, food coloring, and baking soda and you’re good to go!
65. Make popcorn dance
A little baking soda, vinegar, and popcorn are perfect for a lesson on density and acid-base reactions. We love 3rd grade science projects like this one that the kids can do themselves with little assistance.
66. Make a lava lamp
If you’re a child of the 1970s, you’ll especially love this science experiment, and your 3rd graders will get a lesson on density, polarity, and acidity while making their very own lava lamp. Create it in a bottle with a lid and they can even take it home with them.
67. Make a robotic hand
We love 3rd grade science projects that double as a math lesson. Learn about anatomy while also brushing up on your measuring skills. Your students will be excited to bring this one home to show off.
68. Grow an avocado tree
This is a great botany lesson that the class can participate in from the beginning with a single avocado to growing a whole tree. You can even try growing more than one under different variables and see which is more successful.
69. Extinguish a flame
This experiment is a simple way to demonstrate that fire, like many things, needs oxygen to sustain itself. Have an adult light the flame and then let the students gather around as you extinguish it slowly with just a glass.
70. Experiment with atmospheric pressure
This one is similar to the previous experiment but with a twist. Students will be amazed at what happens to the surrounding water once the flame uses up the oxygen in the cup.
71. Float an egg
Some of the best 3rd grade science projects require minimal materials and process to demonstrate a big lesson. This one is a simple way to teach young students about density. Demonstrate how an egg sinks in a cup of regular water but floats in a cup of salt water. Then, explain that the salt water is denser than fresh water. Since the egg is less dense than the salt water, it floats!
72. Dazzle with a toothpick star
This one will even amaze your coworkers. Break apart toothpicks and lay them out in the shape of a closed star. Introduce water into the center and watch as they expand into a star shape. It’s a very cool way to teach about capillary action.
73. Make a flyer
Since kids love paper airplanes, this STEM project is sure to be a hit. All you’ll need is some paper, straws, tape, and scissors.
74. Explode a snowman
Before getting started, have students draw a face for their snowman on ziplock bags. Then have them mix baking soda (a base) with vinegar (an acid). This experiment is a great way to teach kids about chemical reactions and how a substance can transform into another substance under the right circumstances.
75. Use raisins to test density
It doesn’t get much easier than this experiment! You’ll need a cup of regular water, a cup of sparkling water, and some raisins. So few materials teach a big lesson on buoyancy and density.
If you liked these 3rd grade science projects, keep up the STEM enthusiasm with these fun and engaging 3rd grade math games .
Plus, sign up for our newsletters to get all the latest teaching tips and tricks straight to your inbox, you might also like.
The Big List of Science Fair Project Ideas, Resources, and More
Options for every age, interest, and skill level! Continue Reading
Copyright © 2024. All rights reserved. 5335 Gate Parkway, Jacksonville, FL 32256